func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(NULL);     long long n, ans = 0, cnt = 0;     cin >> n;     vector<long long> a(n), pref(n + 1);     for (auto& i : a) cin >> i;     pref[0] = a[0];     for (int i = 1; i < n; ++i) pref[i] += pref[i - 1] + a[i];     if (pref[n - 1] % 3 || n < 3) return cout << 0, 0;     long long s = pref[n - 1] / 3;     for (int i = 0; i < n - 1; ++i) {       if (pref[i] == 2 * s) ans += cnt;       if (pref[i] == s) ++cnt;     }     cout << ans <<   n ;   }   