func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, a, b;   vector<vector<int> > adj;   vector<int> col;   queue<int> x, y;   void colorear(int u, int c) {     col[u] = c;     for (int v : adj[u])       if (col[v] == -1) colorear(v, 1 - c);   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cin >> n;     adj = vector<vector<int> >(2 * n + 2);     for (int i = 0; i < n; i++) {       cin >> a >> b;       adj[a].push_back(b);       adj[b].push_back(a);       x.push(a);       y.push(b);       if (a % 2) {         adj[a].push_back(a + 1);         adj[a + 1].push_back(a);       }       if (b % 2) {         adj[b].push_back(b + 1);         adj[b + 1].push_back(b);       }     }     col = vector<int>(2 * n + 2, -1);     for (int i = 1; i <= 2 * n; i++) {       if (col[i] == -1) {         colorear(i, 0);       }     }     while (n--) {       cout << col[x.front()] + 1 <<     << col[y.front()] + 1 <<   n ;       x.pop();       y.pop();     }     return 0;   }   