practice_codes_dsa/tempCodeRunnerFile.C at main · Rupu-techu/practice_codes_dsa · GitHub

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#include<stdio.h>
#include<ctype.h>
#define MAX 50
int stack[MAX],top=-1;

void push(int c){
    stack[++top]=c;
}

int pop(){
    return stack[top--];
}

int evaluate_postfix(char postfix[]){
    int a,b,i=0,result;
    char ch;
    while(postfix[i]!='\0'){
        ch=postfix[i];
        if(isdigit(ch)){
            push(ch - '0');
        }
        else {
            b=pop();
            a=pop();
            switch(ch){
                case '+':
                result=a+b;
                break;

                case '-':
                result=a-b;
                break;

                case '*':
                result=a*b;
                break;

                case '/':
                result=a/b;
                break;
            }
            push(result);
        }
        i++;
    }
    result=pop();
    return result;
}
int main(){
    char postfix[MAX];
    int result;
    printf("enetr nthe postfix expression:");
    scanf("%s",postfix);

    result=evaluate_postfix(postfix);

    printf("required evaluation is:%d",result);
    return 0;
}