OJ Board

I tried all test cases on the thread, but I still got WA.
What's wrong with my code? :cry:

#include<iostream>
using namespace std;

int main(){
char t, stack[50+1] = {'@'};
int n, pri[255] = {}, top;
pri['@'] = -1, pri['+'] = pri['-'] = 1, pri['*'] = pri['/'] = 2,
pri['('] = 4, pri[')'] = 0 ...