Help required for ONP

general
,
1

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

void del(char * stk, int *top, char * res, int *rest);

int main()
{
int t, i=0, j=0, top=-1, rest=-1, l=0;
char expr[400]={'\0'};
char stk[50]={'\0'}, res[400]={'\0'};

scanf("%d", &t);

for (i=0;i<t;i++) {
    scanf("%s", expr);
    l=strlen(expr);
    rest = -1;
    top=-1;
    for (j=0;j<l;j++) {
        switch(expr[j])
        {
            case '(': stk[++top] = '(';
                    break;
            case '+':
            case '-':
            case '*':
            case '/':
            case '^':
                    stk[++top] = expr[j];
                    break;
            case ')':
                    del(stk, &top, res, &rest);
                    break;
            default: res[++rest] = expr[j];
        }
    }
    printf("%s\n", res);
}
return 0;
}

void del(char * stk, int *top, char * res, int *rest) {
do {
        res[++(*rest)] = stk[*(top)];
        stk[(*top)--]='\0';
} while(stk[*top]!='(' && *top>=0);
      (*top)--;
}

The compiler which it runs on (code::blocks12.11), it gives correct answer. On codechef it says that it gives the wrong answer.

2

You are not initializing the stack (to null in your case) for each test case. So whenever the previous input has a larger expression than current input, your code will give wrong answer. E.g. try following case:

3

((a+t)*((b+(a+c))^(c+d)))

((a+b)*(z+x))

(a+(b*c))

Your code gives WA for this.
Initialize the stack to null for every test case.

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