Subarray Sums II

#include <iostream>
#include <vector>
#include <map>
using namespace std;

using ll = long long int;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    ll x;
    cin >> n >> x;
    vector<ll> nums(n);
    for (int i = 0; i < n; i++) {
        cin >> nums[i];
    }

    map<ll, ll> prefixCount;
    ll currentSum = 0;
    ll count = 0;
    prefixCount[0] = 1;

    for (int i = 0; i < n; i++) {
        currentSum += nums[i];
        ll neededSum = currentSum - x;
        if (prefixCount.find(neededSum) != prefixCount.end()) {
            count += prefixCount[neededSum];
        }
        prefixCount[currentSum]++;
    }

    cout << count << '\n';
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED