modified and updated
This commit is contained in:
parent
44e766514e
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6ff1894732
6 changed files with 674 additions and 7 deletions
201
OS/C/Week11/q1.c
Normal file
201
OS/C/Week11/q1.c
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#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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#define MAX 100
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// Function for SSTF (Shortest Seek Time First)
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void sstf(int arr[], int n, int head) {
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int visited[MAX] = {0}, total_seek = 0, current = head;
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printf("\nSSTF Sequence:\n%d ", current);
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for (int count = 0; count < n; count++) {
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int index = -1, minDist = 1e9;
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for (int i = 0; i < n; i++) {
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if (!visited[i]) {
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int dist = abs(arr[i] - current);
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if (dist < minDist) {
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minDist = dist;
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index = i;
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}
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}
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}
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visited[index] = 1;
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total_seek += minDist;
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current = arr[index];
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printf("-> %d ", current);
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}
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printf("\nTotal Seek Time: %d\n", total_seek);
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}
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// Helper function: Bubble sort in ascending order
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void sortAsc(int arr[], int n) {
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for (int i = 0; i < n - 1; i++)
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for (int j = i + 1; j < n; j++)
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if (arr[i] > arr[j]) {
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int temp = arr[i];
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arr[i] = arr[j];
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arr[j] = temp;
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}
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}
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// Helper function: Bubble sort in descending order
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void sortDesc(int arr[], int
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for (int i = 0; i < n - 1; i++)
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for (int j = i + 1; j < n; j++)
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if (arr[i] < arr[j]) {
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int temp = arr[i];
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arr[i] = arr[j];
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arr[j] = temp;
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}
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}
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// Function for SCAN (Elevator Algorithm)
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// Assumes movement is towards the left first, then reverses.
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void scan(int arr[], int n, int head, int disk_size) {
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int left[MAX], right[MAX], l = 0, r = 0;
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for (int i = 0; i < n; i++) {
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if (arr[i] < head)
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left[l++] = arr[i];
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else
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right[r++] = arr[i];
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}
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sortDesc(left, l);
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sortAsc(right, r);
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int total_seek = 0, current = head;
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printf("\nSCAN Sequence:\n%d ", current);
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// Service left side (moving toward 0)
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for (int i = 0; i < l; i++) {
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total_seek += abs(current - left[i]);
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current = left[i];
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printf("-> %d ", current);
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}
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// If not already at 0, move to 0
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if (current != 0) {
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total_seek += current;
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current = 0;
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printf("-> %d ", current);
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}
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// Then service right side (moving right)
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for (int i = 0; i < r; i++) {
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total_seek += abs(right[i] - current);
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current = right[i];
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printf("-> %d ", current);
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}
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printf("\nTotal Seek Time: %d\n", total_seek);
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}
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// Function for C-SCAN (Circular SCAN)
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// Assumes movement to the right; after reaching the end, the head jumps to 0.
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void cscan(int arr[], int n, int head, int disk_size) {
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int left[MAX], right[MAX], l = 0, r = 0;
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for (int i = 0; i < n; i++) {
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if (arr[i] < head)
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left[l++] = arr[i];
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else
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right[r++] = arr[i];
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}
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sortAsc(left, l);
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sortAsc(right, r);
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int total_seek = 0, current = head;
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printf("\nC-SCAN Sequence:\n%d ", current);
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// Service requests to the right
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for (int i = 0; i < r; i++) {
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total_seek += abs(right[i] - current);
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current = right[i];
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printf("-> %d ", current);
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}
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// Go to the end if not reached
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if (current != disk_size - 1) {
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total_seek += abs(disk_size - 1 - current);
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current = disk_size - 1;
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printf("-> %d ", current);
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}
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// Jump to beginning (simulate wrap-around)
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total_seek += (disk_size - 1);
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current = 0;
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printf("-> %d ", current);
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// Service the left side
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for (int i = 0; i < l; i++) {
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total_seek += abs(left[i] - current);
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current = left[i];
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printf("-> %d ", current);
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}
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printf("\nTotal Seek Time: %d\n", total_seek);
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}
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// Function for C-LOOK
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// Assumes movement to the right; after the furthest request, it jumps to the smallest request.
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void clook(int arr[], int n, int head) {
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int left[MAX], right[MAX], l = 0, r = 0;
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for (int i = 0; i < n; i++) {
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if (arr[i] < head)
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left[l++] = arr[i];
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else
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right[r++] = arr[i];
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}
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sortAsc(left, l);
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sortAsc(right, r);
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int total_seek = 0, current = head;
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printf("\nC-LOOK Sequence:\n%d ", current);
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// Service the right side
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for (int i = 0; i < r; i++) {
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total_seek += abs(right[i] - current);
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current = right[i];
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printf("-> %d ", current);
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}
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// Jump to the leftmost request if any exist on the left
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if (l > 0) {
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total_seek += abs(current - left[0]);
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current = left[0];
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printf("-> %d ", current);
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for (int i = 1; i < l; i++) {
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total_seek += abs(left[i] - current);
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current = left[i];
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printf("-> %d ", current);
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}
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}
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printf("\nTotal Seek Time: %d\n", total_seek);
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}
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int main() {
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int choice, n, head, disk_size;
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int arr[MAX];
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printf("Menu:\n");
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printf("1. SSTF\n");
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printf("2. SCAN\n");
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printf("3. C-SCAN\n");
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printf("4. C-LOOK\n");
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printf("Enter your choice: ");
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scanf("%d", &choice);
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printf("Enter number of requests: ");
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scanf("%d", &n);
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printf("Enter the request queue (space separated): ");
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for (int i = 0; i < n; i++) {
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scanf("%d", &arr[i]);
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}
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printf("Enter initial head position: ");
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scanf("%d", &head);
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if (ce == 2 || choice == 3) { // SCAN and C-SCAN require the disk size
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printf("Enter disk size: ");
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scanf("%d", &disk_size);
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}
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switch (choice) {
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case 1:
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sstf(arr, n, head);
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break;
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case 2:
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scan(arr, n, head, disk_size);
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break;
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case 3:
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cscan(arr, n, head, disk_size);
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break;
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case 4:
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clook(arr, n, head);
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break;
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default:
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printf("Invalid choice!\n");
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}
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return 0;
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}
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234
OS/C/Week11/qq1.c
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234
OS/C/Week11/qq1.c
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#include <stdio.h>
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#include <stdlib.h>
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#include <limits.h>
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void sstf(int requests[], int n, int head) {
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int total_seek = 0;
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int completed = 0;
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int visited[100] = {0};
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int current = head;
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printf("\nSSTF Disk Scheduling\n");
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printf("Seek Sequence: %d", head);
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while (completed < n) {
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int min_distance = INT_MAX;
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int min_index = -1;
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for (int i = 0; i < n; i++) {
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if (!visited[i]) {
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int distance = abs(requests[i] - current);
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if (distance < min_distance) {
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min_distance = distance;
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min_index = i;
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}
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}
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}
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visited[min_index] = 1;
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current = requests[min_index];
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total_seek += min_distance;
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completed++;
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printf(" -> %d", current);
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}
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printf("\nTotal Seek Time: %d\n", total_seek);
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}
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void scan(int requests[], int n, int head, int disk_size) {
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int total_seek = 0;
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int direction = 1; // 1 for moving right, 0 for moving left
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int current = head;
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printf("\nSCAN Disk Scheduling\n");
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printf("Seek Sequence: %d", head);
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// Sort requests
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for (int i = 0; i < n; i++) {
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for (int j = 0; j < n - i - 1; j++) {
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if (requests[j] > requests[j + 1]) {
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int temp = requests[j];
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requests[j] = requests[j + 1];
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requests[j + 1] = temp;
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}
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}
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}
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// Find position of head in sorted array
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int index;
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for (index = 0; index < n; index++) {
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if (requests[index] >= head)
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break;
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}
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// Move right
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for (int i = index; i < n; i++) {
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current = requests[i];
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printf(" -> %d", current);
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total_seek += abs(current - head);
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head = current;
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}
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// Move to the end of disk
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printf(" -> %d", disk_size - 1);
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total_seek += abs(disk_size - 1 - head);
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head = disk_size - 1;
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// Move left
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for (int i = index - 1; i >= 0; i--) {
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current = requests[i];
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printf(" -> %d", current);
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total_seek += abs(current - head);
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head = current;
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}
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printf("\nTotal Seek Time: %d\n", total_seek);
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}
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void cscan(int requests[], int n, int head, int disk_size) {
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int total_seek = 0;
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int current = head;
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printf("\nC-SCAN Disk Scheduling\n");
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printf("Seek Sequence: %d", head);
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// Sort requests
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for (int i = 0; i < n; i++) {
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for (int j = 0; j < n - i - 1; j++) {
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if (requests[j] > requests[j + 1]) {
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int temp = requests[j];
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requests[j] = requests[j + 1];
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requests[j + 1] = temp;
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}
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}
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}
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// Find position of head in sorted array
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int index;
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for (index = 0; index < n; index++) {
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if (requests[index] >= head)
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break;
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}
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// Move right
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for (int i = index; i < n; i++) {
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current = requests[i];
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printf(" -> %d", current);
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total_seek += abs(current - head);
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head = current;
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}
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// Move to the end of disk
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printf(" -> %d", disk_size - 1);
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total_seek += abs(disk_size - 1 - head);
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// Move to the beginning
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printf(" -> 0");
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total_seek += disk_size - 1;
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head = 0;
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// Move right again
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for (int i = 0; i < index; i++) {
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current = requests[i];
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printf(" -> %d", current);
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total_seek += abs(current - head);
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head = current;
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}
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printf("\nTotal Seek Time: %d\n", total_seek);
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}
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void clook(int requests[], int n, int head) {
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int total_seek = 0;
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int current = head;
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printf("\nC-LOOK Disk Scheduling\n");
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printf("Seek Sequence: %d", head);
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// Sort requests
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for (int i = 0; i < n; i++) {
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for (int j = 0; j < n - i - 1; j++) {
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if (requests[j] > requests[j + 1]) {
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int temp = requests[j];
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requests[j] = requests[j + 1];
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requests[j + 1] = temp;
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}
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}
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}
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// Find position of head in sorted array
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int index;
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for (index = 0; index < n; index++) {
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if (requests[index] >= head)
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break;
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}
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// Move right
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for (int i = index; i < n; i++) {
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current = requests[i];
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printf(" -> %d", current);
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total_seek += abs(current - head);
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head = current;
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}
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// Move to first request
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for (int i = 0; i < index; i++) {
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current = requests[i];
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printf(" -> %d", current);
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total_seek += abs(current - head);
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head = current;
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}
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printf("\nTotal Seek Time: %d\n", total_seek);
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}
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int main() {
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int requests[100], n, head, disk_size, choice;
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printf("Enter the number of disk requests: ");
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scanf("%d", &n);
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printf("Enter the disk requests: ");
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for (int i = 0; i < n; i++) {
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scanf("%d", &requests[i]);
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}
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printf("Enter the initial head position: ");
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scanf("%d", &head);
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printf("Enter the disk size (0 to size-1): ");
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scanf("%d", &disk_size);
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do {
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printf("\n\nDisk Scheduling Algorithms\n");
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printf("1. SSTF (Shortest Seek Time First)\n");
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printf("2. SCAN\n");
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printf("3. C-SCAN\n");
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printf("4. C-LOOK\n");
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printf("5. Exit\n");
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printf("Enter your choice: ");
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scanf("%d", &choice);
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switch (choice) {
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case 1:
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sstf(requests, n, head);
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break;
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case 2:
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scan(requests, n, head, disk_size);
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break;
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case 3:
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cscan(requests, n, head, disk_size);
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break;
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case 4:
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clook(requests, n, head);
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break;
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case 5:
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printf("Exiting program...\n");
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break;
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default:
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printf("Invalid choice!\n");
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}
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} while (choice != 5);
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return 0;
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}
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0
OS/C/Week11/test.c
Normal file
0
OS/C/Week11/test.c
Normal file
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