1068

이준휘/n1068.java

@@ -0,0 +1,47 @@
+package baekjoon;
+import java.util.*;
+public class n1068 {
+	static int[] arr = new int[50];
+	static boolean[][] vertex = new boolean[50][50];
+	static boolean[] visited = new boolean[50]; 
+	static int result=0;
+	static void dfs(int n) {
+		boolean check = false;
+		//System.out.println(n);
+		visited[n] = true;
+		for(int i = 0; i<50; i++) {
+			if(vertex[n][i] && !visited[i]) {
+				visited[i] = true;
+				dfs(i);
+				check = true;
+			}
+		}
+		if(!check) result++;
+
+	}
+	public static void main(String[] args) {
+		Scanner sc = new Scanner(System.in);
+		int n = sc.nextInt();
+		int top = 0;
+		for(int i = 0; i<n; i++) {
+			arr[i] = sc.nextInt();
+			if(arr[i] == -1) {
+				top = i;
+				continue;
+			}
+			vertex[arr[i]][i] = true;
+			vertex[i][arr[i]] = true;
+		}
+		int m = sc.nextInt();
+		if(m == top) {
+			System.out.println(0);
+			return;
+		}
+		for(int i = 0; i<50; i++) {
+			vertex[m][i] = false;
+			vertex[i][m] = false;
+		}
+		dfs(top);
+		System.out.println(result);
+	}
+}