leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
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1466.cpp (863B)

      1 class Solution {
      2   public:
      3     int minReorder(int n, vector<vector<int>> &connections) {
      4         unordered_set<string> us;
      5         vector<bool> visited(n, false);
      6         vector<vector<int>> adj(n, vector<int>());
      7 
      8         for (auto &e : connections) {
      9             us.insert(to_string(e[0]) + " " + to_string(e[1]));
     10             adj[e[0]].push_back(e[1]);
     11             adj[e[1]].push_back(e[0]);
     12         }
     13 
     14         int res = 0;
     15 
     16         stack<int> st;
     17         st.push(0);
     18         visited[0] = true;
     19         while (!st.empty()) {
     20             int root = st.top();
     21             st.pop();
     22             for (auto c : adj[root])
     23                 if (!visited[c]) {
     24                     if (!us.count(to_string(c) + " " + to_string(root))) res++;
     25                     visited[c] = true;
     26                     st.push(c);
     27                 }
     28         }
     29         return res;
     30     }
     31 };