func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mxn = 1e5 + 5;   int n, a[mxn], c[mxn];   bool vis[mxn];   int main() {     scanf( %d , &n);     for (int(i) = (int)(1); (i) <= (int)(n); ++(i)) scanf( %d , a + i);     int cnt = 0;     for (int(i) = (int)(n); (i) >= (int)(1); --(i)) {       c[i] = c[i + 1] + (vis[a[i]] == 0);       vis[a[i]] = 1;     }     long long ans = 0;     memset(vis, 0, sizeof(vis));     for (int(i) = (int)(1); (i) <= (int)(n); ++(i))       if (!vis[a[i]]) {         vis[a[i]] = 1;         ans += c[i + 1];       }     return 0 * printf( %lld n , ans);   }   