백준 트리 dfs

Author: ympark99

1068.cpp

@@ -0,0 +1,42 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int root, del, leaf;
+vector<int> v[51];
+
+int dfs(int node){
+    if(node == del)
+        return -1;
+    if(!v[node].size()){
+        leaf++;
+        return 0;
+    }
+    for(int i = 0; i < v[node].size(); i++){
+        int tmp = dfs(v[node][i]);
+        if(tmp == -1 && v[node].size() == 1)
+            leaf++;
+    }
+    return 0;
+}
+
+int main() {
+    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
+
+    int N; cin >> N;
+
+    int num;
+    int idx = 0;
+    for(int i = 0; i < N; i++){
+        cin >> num;
+        if(num == -1)
+            root = i;
+        else v[num].push_back(i);
+    }
+    cin >> del;
+    dfs(root);
+
+    cout << leaf << '\n';
+}