Subarray Sum II

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int n;
ll x;
vector<ll> arr;
ll ans;

int main(){
    //freopen("subsumsII.in", "r", stdin);

    cin >> n >> x;
    arr.resize(n+1);
    for(int i=0; i<n; i++){
        cin >> arr[i];
    }
    ll sum = 0;
    //unordered_map<ll, int> freq;
    map<ll, int> freq;
    //map better performance
    //unordered map result in time limit exceeded
    freq[0] = 1;
    for(int i=0; i<n; i++){
        sum+=arr[i];
        ll val = sum-x;
        ans+=freq[val];
        freq[sum]++;
    }
    cout << ans << '\n';

    return 0;
}