func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxN = 200010;   int a[maxN];   long long presum[maxN];   int n;   set<long long> st;   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) {       scanf( %d , &a[i]);       presum[i] = presum[i - 1] + a[i];     }     for (int i = 1; i <= n; i++) {       long long M = 1;       while (M <= a[i]) M += M;       for (int j = i + 2; j <= n && presum[j - 1] - presum[i] <= M; j++)         if ((a[i] ^ a[j]) == (presum[j - 1] - presum[i]))           st.insert(1LL * i * n + j);       for (int j = i - 2; j >= 1 && presum[i - 1] - presum[j] <= M; j--)         if ((a[j] ^ a[i]) == (presum[i - 1] - presum[j]))           st.insert(1LL * j * n + i);     }     printf( %d n , (int)st.size());     return 0;   }   