diff --git a/DS/C/Lab/Week5/InfixToPostfix.c b/DS/C/Lab/Week5/InfixToPostfix.c
index b543de6..6c87ad9 100644
--- a/DS/C/Lab/Week5/InfixToPostfix.c
+++ b/DS/C/Lab/Week5/InfixToPostfix.c
@@ -1,70 +1,91 @@
 #include <stdio.h>
 #include <string.h>
-#include <ctype.h>
 
 #define MAX_SIZE 100
 
 char stack[MAX_SIZE];
 int top = -1;
 
-void push(char item) {
-    if (top >= MAX_SIZE - 1) {
+void push(char item)
+{
+    if (top >= MAX_SIZE - 1)
+    {
         printf("Stack Overflow\n");
         return;
     }
     stack[++top] = item;
 }
 
-char pop() {
-    if (top < 0) {
+char pop()
+{
+    if (top < 0)
+    {
         printf("Stack Underflow\n");
         return -1;
     }
     return stack[top--];
 }
 
-int precedence(char symbol) {
-    switch (symbol) {
-        case '^': return 3;
-        case '*':
-        case '/': return 2;
-        case '+':
-        case '-': return 1;
-        default: return 0;
+int precedence(char symbol)
+{
+    switch (symbol)
+    {
+    case '^':
+        return 3;
+    case '*':
+    case '/':
+        return 2;
+    case '+':
+    case '-':
+        return 1;
+    default:
+        return 0;
     }
 }
 
-void infixToPostfix(char infix[], char postfix[]) {
+void infixToPostfix(char infix[], char postfix[])
+{
     int i, j = 0;
     char symbol, next;
-    for (i = 0; i < strlen(infix); i++) {
+    for (i = 0; i < strlen(infix); i++)
+    {
         symbol = infix[i];
-        if (isalnum(symbol)) {
+        if ((symbol >= 'a' && symbol <= 'z') || (symbol >= 'A' && symbol <= 'Z') || (symbol >= '0' && symbol <= '9'))
+        {
             postfix[j++] = symbol;
-        } else if (symbol == '(') {
+        }
+        else if (symbol == '(')
+        {
             push(symbol);
-        } else if (symbol == ')') {
-            while ((next = pop()) != '(') {
+        }
+        else if (symbol == ')')
+        {
+            while ((next = pop()) != '(')
+            {
                 postfix[j++] = next;
             }
-        } else {
-            while (top > -1 && precedence(stack[top]) >= precedence(symbol)) {
+        }
+        else
+        {
+            while (top > -1 && precedence(stack[top]) >= precedence(symbol))
+            {
                 postfix[j++] = pop();
             }
             push(symbol);
         }
     }
-    while (top > -1) {
+    while (top > -1)
+    {
         postfix[j++] = pop();
     }
     postfix[j] = '\0';
 }
 
-int main() {
+int main()
+{
     char infix[MAX_SIZE], postfix[MAX_SIZE];
     printf("Enter infix expression: ");
-    fgets(infix, MAX_SIZE, stdin);
-    infix[strcspn(infix, "\n")] = 0;  // Remove newline if present
+    gets(infix);
     infixToPostfix(infix, postfix);
     printf("Postfix expression: %s\n", postfix);
     return 0;
diff --git a/DS/C/Lab/Week5/PostfixCheck.c b/DS/C/Lab/Week5/PostfixCheck.c
index 770015b..8fe9a89 100644
--- a/DS/C/Lab/Week5/PostfixCheck.c
+++ b/DS/C/Lab/Week5/PostfixCheck.c
@@ -6,61 +6,80 @@
 int stack[MAX_SIZE];
 int top = -1;
 
-void push(int item) {
-    if (top >= MAX_SIZE - 1) {
+void push(int item)
+{
+    if (top >= MAX_SIZE - 1)
+    {
         printf("Stack Overflow\n");
         return;
     }
     stack[++top] = item;
 }
 
-int pop() {
-    if (top < 0) {
+int pop()
+{
+    if (top < 0)
+    {
         printf("Stack Underflow\n");
-        return -1;  // Return a sentinel value instead of exiting
+        return -1;
     }
     return stack[top--];
 }
 
-int isDigit(char c) {
+int isDigit(char c)
+{
     return c >= '0' && c <= '9';
 }
 
-int evaluatePostfix(char* exp) {
+int evaluatePostfix(char *exp)
+{
     int i, operand1, operand2, result;
-    
-    for (i = 0; exp[i] != '\0'; i++) {
-        if (isDigit(exp[i])) {
+
+    for (i = 0; exp[i] != '\0'; i++)
+    {
+        if (isDigit(exp[i]))
+        {
             push(exp[i] - '0');
-        } else {
+        }
+        else
+        {
             operand2 = pop();
             operand1 = pop();
-            switch (exp[i]) {
-                case '+': push(operand1 + operand2); break;
-                case '-': push(operand1 - operand2); break;
-                case '*': push(operand1 * operand2); break;
-                case '/': 
-                    if (operand2 == 0) {
-                        printf("Error: Division by zero\n");
-                        return -1;  // Return a sentinel value instead of exiting
-                    }
-                    push(operand1 / operand2); 
-                    break;
+            switch (exp[i])
+            {
+            case '+':
+                push(operand1 + operand2);
+                break;
+            case '-':
+                push(operand1 - operand2);
+                break;
+            case '*':
+                push(operand1 * operand2);
+                break;
+            case '/':
+                if (operand2 == 0)
+                {
+                    printf("Error: Division by zero\n");
+                    return -1;
+                }
+                push(operand1 / operand2);
+                break;
             }
         }
     }
     return pop();
 }
 
-int main() {
+int main()
+{
     char exp[MAX_SIZE];
     printf("Enter a postfix expression: ");
-    fgets(exp, MAX_SIZE, stdin);
-    exp[strcspn(exp, "\n")] = 0;  // Remove newline if present
-    
+    gets(exp);
+
     int result = evaluatePostfix(exp);
-    if (result != -1) {
+    if (result != -1)
+    {
         printf("Result: %d\n", result);
     }
     return 0;
-}
\ No newline at end of file
+}
diff --git a/DS/C/Lab/Week5/PostfixToInfix.c b/DS/C/Lab/Week5/PostfixToInfix.c
index b207c46..e8c4f14 100644
--- a/DS/C/Lab/Week5/PostfixToInfix.c
+++ b/DS/C/Lab/Week5/PostfixToInfix.c
@@ -30,7 +30,7 @@ int isOperator(char c) {
 
 void postfixToInfix(const char* postfix) {
     char op1[MAX_EXPR_LEN], op2[MAX_EXPR_LEN], temp[MAX_EXPR_LEN];
-    
+
     for (int i = 0; postfix[i] != '\0'; i++) {
         if (!isOperator(postfix[i])) {
             temp[0] = postfix[i];
@@ -43,7 +43,7 @@ void postfixToInfix(const char* postfix) {
             push(temp);
         }
     }
-    
+
     printf("Infix expression: %s\n", stack[top]);
 }
 
@@ -53,4 +53,4 @@ int main() {
     gets(postfix);
     postfixToInfix(postfix);
     return 0;
-}
\ No newline at end of file
+}