[BOJ] 1068 트리 (G5)

Author: uiop5809

박예진/6주차/260206.cpp

@@ -0,0 +1,46 @@
+// https://www.acmicpc.net/problem/1068
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int N, dv;
+bool flag[51];
+vector <int> parent[51];
+
+void dfs(int dv){
+  flag[dv] = true;
+  if (parent[dv].size() == 0) {
+    return;
+  }
+
+  for(int i = 0; i < parent[dv].size(); i++){
+    dfs(parent[dv][i]);
+  }
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL); cout.tie(NULL);
+
+  cin >> N;
+  for(int i = 0; i < N; i++){
+    int v;
+    cin >> v;
+    if (v == -1) continue;
+    parent[v].push_back(i);
+  }
+  cin >> dv;
+  dfs(dv);
+
+  int res = 0;
+  for(int i = 0; i < N; i++){
+    int cnt = 0;
+    for(int j = 0; j < parent[i].size(); j++){
+      if (flag[parent[i][j]]) cnt++;
+    }
+    if (!flag[i] && cnt == parent[i].size()) res++;
+  }
+  cout << res;
+
+  return 0;
+}