prefixSumII.cpp

#include <bits/stdc++.h>
using namespace std;

struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }
  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};

void solve() {
  int n, k;
  cin >> n >> k;
  vector<long long> v(n + 1, 0);
  for (int i = 1; i <= n; i++) {
    cin >> v[i];
    v[i] += v[i - 1];
  }
  unordered_map<long long, int, custom_hash> m;
  long long com;
  long long res = 0;
  for (long long &x : v) {
    com = x - k;
    auto it = m.find(com);
    if (it != m.end()) {
      res += it->second;
    }
    m[x]++;
  }
  cout << res;
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  solve();
}