func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAX = 1e5 + 9;   int pre[MAX], suf[MAX], a[MAX];   long long ans = 0, cnt = 0;   int main() {     int n;     cin >> n;     for (int i = 0; i < n; i++)       cin >> a[i], pre[i] = (i > 0 ? pre[i - 1] + a[i] : a[i]);     int sum = pre[n - 1] / 3;     if (pre[n - 1] % 3 != 0) return cout << 0, 0;     for (int i = n - 1; i >= 0; i--) suf[i] = suf[i + 1] + a[i];     if (pre[0] == sum) cnt++;     for (int i = 2; i < n; i++) {       if (suf[i] == sum) ans += cnt;       if (pre[i - 1] == sum) cnt++;     }     cout << ans;   }   