func_code_string: #include <bits/stdc++.h>   using namespace std;   template <class T>   inline bool chmax(T &a, T b) {     if (a < b) {       a = b;       return true;     }     return false;   }   template <class T>   inline bool chmin(T &a, T b) {     if (a > b) {       a = b;       return true;     }     return false;   }   const long long INF = 1e18;   long long N;   long long a[1050];   vector<string> ans, trueans;   vector<vector<int>> Prev, Next;   void f(int item) {     int idx1 = 0;     int idx2 = 1;     Next.clear();     for (auto v : Prev) {       if (v.size() <= 1) continue;       idx1 = v[0];       idx2 = v[1];     }     ans[idx1][item] =  1 ;     ans[idx2][item] =  0 ;     long long one = a[item] - 1;     for (int i = 0; i <= N; i++) {       if (i == idx2 or i == idx1) continue;       if (one) {         one--;         ans[i][item] =  1 ;       } else {         ans[i][item] =  0 ;       }     }     for (auto v : Prev) {       vector<int> u[2];       for (auto tmp : v) {         if (ans[tmp][item] ==  0 )           u[0].push_back(tmp);         else           u[1].push_back(tmp);       }       for (int i = 0; i < 2; i++) {         if (u[i].size()) Next.push_back(u[i]);       }     }     swap(Prev, Next);   }   int main() {     cin >> N;     for (int i = 0; i < N; i++) cin >> a[i];     ans.resize(N + 1, string(N,  0 ));     Prev.push_back({});     for (int i = 0; i <= N; i++) {       Prev[0].push_back(i);     }     for (int i = 0; i < N; i++) f(i);     for (auto v : Prev) {       assert(v.size() == 1);     }     for (auto s : ans) {       if (s != string(N,  0 )) trueans.push_back(s);     }     cout << trueans.size() <<   n ;     for (auto s : trueans) {       cout << s <<   n ;     }     return 0;   }   