func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 1000010;   const int s = 1000000;   int n;   int b[maxn];   int p[maxn];   int c[maxn];   vector<int> ans;   int main() {     scanf( %d , &n);     int t;     for (int i = 0; i < n; ++i) {       scanf( %d , &t);       b[t] = 1;       p[i] = t;     }     int l = 1;     for (int i = 0; i < n; ++i) {       if (c[p[i]] == 0) {         if (b[s - p[i] + 1] == 0) {           ans.push_back(s - p[i] + 1);           b[s - p[i] + 1] = 1;         } else {           while (b[l] || b[s - l + 1]) {             l++;           }           ans.push_back(l);           b[l] = 1;           ans.push_back(s - l + 1);           b[s - l + 1] = 1;           c[s - p[i] + 1] = 1;         }       }     }     printf( %ld n , ans.size());     for (int i = 0; i < ans.size(); ++i) {       if (i) printf(   );       printf( %d , ans[i]);     }     printf(  n );     return 0;   }   