Wrong answer even in the sample case

#1

#include<bits/stdc++.h>
using namespace std;
int main() {
string s; cin >> s;
int cnt[100];
for(int i = 0; i < s.length(); i++){
cnt[s[i] - ‘A’]++;
}
int max_val = 0, max_idx = 0;
for(int i = 0; i < 100; i++)
if(cnt[i] > max_val) max_val = cnt[i], max_idx = i;
cout << char(‘A’ + max_idx) << endl;
return 0;
}

#2

Initialize cnt array with zero