func_code_string: #include <bits/stdc++.h>   using namespace std;   int a[1000010];   long long cnt[1000010];   int main() {     ios::sync_with_stdio(0);     int n;     cin >> n;     long long s = 0;     for (int i = 0; i < n; ++i) {       cin >> a[i];       s += a[i];     }     if (s % 3 != 0)       cout <<  0 n ;     else {       s /= 3;       long long ss = 0;       for (int i = n - 1; i >= 0; --i) {         ss += a[i];         if (ss == s) cnt[i] = 1;       }       for (int i = n - 2; i >= 0; --i) cnt[i] += cnt[i + 1];       long long ans = 0;       ss = 0;       for (int i = 0; i + 2 < n; ++i) {         ss += a[i];         if (ss == s) ans += cnt[i + 2];       }       cout << ans <<   n ;     }     return 0;   }   