Data Structure lab

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <math.h>

#define MAX 100

char stack[MAX];
int top = -1;

void push(char c) {
    stack[++top] = c;
}
char pop() {
    return (top == -1) ? '\0' : stack[top--];
}
char peek() {
    return (top == -1) ? '\0' : stack[top];
}

int precedence(char op) {
    switch (op) {
        case '^': return 3;
        case '*': case '/': case '%': return 2;
        case '+': case '-': return 1;
        default: return 0;
    }
}

int isRightAssociative(char op) {
    return (op == '^');
}

void infixToPostfix(char *infix, char *postfix) {
    int i = 0, k = 0;
    char ch;
    while ((ch = infix[i++]) != '\0') {
        if (isalnum(ch)) {
            postfix[k++] = ch;
        }
        else if (ch == '(') {
            push(ch);
        }
        else if (ch == ')') {
            while (peek() != '(')
                postfix[k++] = pop();
            pop(); // remove '('
        }
        else { // operator
            while (precedence(peek()) > precedence(ch) ||
                  (precedence(peek()) == precedence(ch) && !isRightAssociative(ch))) {
                postfix[k++] = pop();
            }
            push(ch);
        }
    }
    while (top != -1)
        postfix[k++] = pop();
    postfix[k] = '\0';
}

int main() {
    char infix[MAX], postfix[MAX];
    printf("Enter Infix Expression: ");
    scanf("%s", infix);

    infixToPostfix(infix, postfix);

    printf("Postfix Expression is: %s\n", postfix);
    return 0;
}


               


  

Enter Infix Expression: (A+B)*C^D    

Postfix Expression is: AB+CD^*