func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long T = 200002;   const long long MAXD = T * T * T;   int n, s;   int N[T];   int PREFP[T];   int SUFL[T];   int main(void) {     cin >> n;     for (int i = (int)1; i <= (int)n; i++) {       cin >> N[i];     }     for (int i = (int)1; i <= (int)n; i++) {       PREFP[i] += N[i] + PREFP[i - 1];     }     for (int i = (int)n; i >= (int)1; i--) {       int k = N[i] == 0 ? 1 : 0;       SUFL[i] = k + SUFL[i + 1];     }     int b = 1;     int e = n;     long long ans = 0;     while (true) {       while (N[b] != 1 && b <= n) {         b++;       }       while (N[e] != 0 && e >= 1) {         e--;       }       if (e > b) {         long long bs = SUFL[b] - SUFL[e + 1];         long long es = PREFP[e] - PREFP[b - 1];         if (bs > es) {           e--;           ans += es;         } else {           b++;           ans += bs;         }       } else {         break;       }     }     cout << ans << endl;     return 0;   }   