I am solving this problem. The code can pass all sample test cases, but get WA in sbmission.
Here is the code:
#include <bits/stdc++.h>
using namespace std;
int main() {
freopen("testcases.txt", "r", stdin);
int testcase;
scanf("%d", &testcase);
while(testcase--) {
int N;
scanf("%d", &N);
string str;
cin >> str;
int count;
int size = (int)str.size();
for(int i = 0; i < size; i++) {
if(str[i] == 'Q') {
count++;
}else {
count--;
}
}
if(count < 0) {
count = 0;
}
if(count <= 0) {
printf("Yes\n");
}else {
printf("No\n");
}
}
return 0;
}