Subarray Sums II

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

int main() {
    long long n, x;
    cin >> n >> x;
    vector<long long> a(n);
    for (long long i = 0; i < n; i++) {
        cin >> a[i];
    }

    unordered_map<long long, long long> prefix_sums;
    long long current_sum = 0, count = 0;
    prefix_sums[0] = 1;

    for (long long i = 0; i < n; i++) {
        current_sum += a[i];
        if (prefix_sums.find(current_sum - x) != prefix_sums.end()) {
            count += prefix_sums[current_sum - x];
        }
        prefix_sums[current_sum]++;
    }

    cout << count << endl;
    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: TIME LIMIT EXCEEDED