Create 2020-A-D.cpp

Author: tmp-coder

Diff for: kick-start/2020-A-D.cpp

@@ -0,0 +1,79 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+struct Node{
+    int son;
+    int cnt;
+    Node():son(-1),cnt(0){};
+};
+
+
+struct Trie{
+    vector<vector<Node>> nodes;
+    Trie(){
+        nodes.push_back(vector<Node>(26));
+    }
+    int add_node(){
+        nodes.push_back(vector<Node>(26));
+        return nodes.size() -1;
+    }
+    void add_string(const string & str){
+        int cur = 0;
+        for(const auto  e : str){
+            int idx = e - 'A';
+            auto &node = nodes[cur][idx];
+            if (node.son == -1){// add new node
+                node.son = add_node();
+            }
+            node.cnt ++;
+            cur = node.son;
+        }
+    }
+    int size(){
+        return nodes.size();
+    }
+};
+
+pair<int,int> dfs(int u,int cnt, int dep,const Trie & trie,int K){
+    int ans =0;
+    int used = 0;
+    for(const auto & e : trie.nodes[u]){
+        if (e.son != -1 && e.cnt >=K){
+            auto ret = dfs(e.son,e.cnt,dep +1, trie, K);
+            ans += ret.first;
+            used += ret.second;
+        }
+    }
+    if ( cnt -used>=K){
+        ans += (cnt - used)/K * dep;
+        used += (cnt - used)/ K * K;
+    }
+    return make_pair(ans, used);
+}
+
+void solve(){
+    int N,K;
+    cin >> N >> K;
+    Trie trie;
+    for(int i=0 ; i< N ; ++i)
+    {
+        string s;
+        cin >> s;
+        trie.add_string(s);
+    }
+    auto ans = dfs(0,N,0,trie,K);
+    cout << ans.first << "\n";
+}
+
+int main(){
+    int T;
+    cin >> T;
+
+    for(int t =1 ; t <= T ; ++ t){
+        cout << "Case #"<<t<<": ";
+
+        solve();
+    }
+    return 0;
+}