CF1398C. Good Subarrays（思维 前缀和）

// Problem: C. Good Subarrays
// Contest: Codeforces - Educational Codeforces Round 93 (Rated for Div. 2)
// URL: https://codeforces.com/problemset/problem/1398/C
// Memory Limit: 256 MB
// Time Limit: 2000 ms
// 
// Powered by CP Editor (https://cpeditor.org)
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn=1e5+100;
int n,a[maxn];
map<ll,ll>mp;
int main(){
  int _;cin>>_;
  while(_--){
    cin>>n;
    for(int i=1;i<=n;i++) scanf("%1d",&a[i]),a[i]--;
    ll ans=0,sum=0;
    mp.clear();
    mp[0]=1;
    for(int i=1;i<=n;i++){
      sum+=a[i];
      ans=ans+mp[sum];
      mp[sum]++;
    }
    cout<<ans<<endl;
  }
  return 0;
}