func_code_string: #include <bits/stdc++.h>   using namespace std;   int main(void) {     int n;     scanf( %d , &n);     long a[n];     long long s = 0, ss = 0;     for (int i = 0; i < n; i++) {       scanf( %ld , &a[i]);       s += a[i];     }     if (s % 3 != 0) {       printf( 0 n );       return 0;     }     s = s / 3;     vector<int> sum1;     vector<int> sum2;     for (int i = 0; i < n - 1; i++) {       ss += a[i];       if (ss == s) sum1.push_back(i);       if (ss == 2 * s) sum2.push_back(i);     }     long long ans = 0;     for (int i = 0; i < sum1.size(); i++) {       ans += sum2.end() - lower_bound(sum2.begin(), sum2.end(), sum1[i] + 1);     }     printf( %I64d n , ans);     return 0;   }   