#include<srdio.h>
#include<stdlib.h>
#include<string.h>
#inclue<ctype.h>

#define MAX_SIZE 101
typedef struct {
    char arr[MAX_SIZE];
    int top;
}CharStack;

void initialize(CharStack*s) {
    s->top=-1;
}
int isEmpty(Charstack*s) {
    return s->top==-1;
}

void  push(CharStack*s,char value) {
    if(s->top>=MAX_SIZE-1) {
        return;
    }

s->arr[++s->top]=value;
}
char peek(CharStack *s) {
    if(isEmpty(s)) {
        return'\0'
    }
    returns->arr[s->top];
}
int precendence(char op){
    if(op=='*' || op =='/'){
        return 1;
    }else if(op =='*' || op =='/') {
        return 2;
    }
    return 0;
}
void infixToPostfix(const char * infix) {
    Charstack operatorStack;
    initialize(&operatorStack);
    char postfix[MAX_SIZE *2];
    int postfixIndex=0;
    int len =strlen(infix);
    for(int i=0;i<=len;i++ ) {
        char currnetChar =infix[i];
        if(isalnum(currentchar)) {
            postfix[postfixIndex++]=currentChar;
        }
        else if(currnetChar =='(') {
            push(&operatorStack,currnetchar);
    }else if(currnetChar ==')') {
        while(!isEmpty(&operatorStack) && peek(&operatorStack)!='(') {
            postfix[postfixIndex++]+pop(&operatorStack);
        }
        if(!isEmpty(&operatorStack)&& peek(&operator Stack)=='('){
            pop(&operatorStack);
        }
    }
    else if(currentChar =='+'||)currentChar =='_'||currentChar =="+"|| currnetChar =='/'){
        while(!isEmpty(&operatorStack) && peek (&operatorStack)!='('&& precendence(peek(&operatorStack))>=precendence(currentChar)) {
            postfix[postfixIndex++]=pop(&operatorStack);
        }
        pus
    }
}