백준 트리 1068

https://www.acmicpc.net/problem/1068

1068번: 트리

ㅠㅠ 1시간만에 해결했네요... 이런문제를 어떻게 20분안에 풀까용 ㅠㅠ 
포인트는 시작점은 어디든 랜덤위치라는것 그리고 삭제 위치 이후로는 dfs 더이상 진행하지않는다. 그리고 카운트는 시작할때 해주고 진행이 끝날때까지 카운트를 하지않습니다.

#include <iostream>
#include <vector>
#include <queue>
#include<string>
#include<algorithm>
#include<cmath>
#include<unordered_map>
#include<map>
#include<stack>
using namespace std;

struct Point {
	int i, j;
	int sum = 0; 
	int cnt=0;
};

void Prints(vector<vector<int>>maps, int n, int m) {
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			cout << maps[i][j] << " ";
		}
		cout << endl;
	}
	cout << endl;
}

void Prints(vector<vector<bool>>maps, int n, int m) {
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			cout << maps[i][j] << " ";
		}
		cout << endl;
	}
	cout << endl;
}
void Prints(vector<vector<char>>maps, int n, int m) {
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			cout << maps[i][j];
		}
		cout << endl;
	}
	cout << endl;
}
void Prints(vector<vector<vector<char>>>maps, int n, int m, int k) {
	for (int t = 0; t < k; t++) {
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < m; j++) {
				cout << maps[t][i][j];
			}
			cout << endl;
		}
		cout << endl;
	}
	cout << endl;
}

void Prints(vector<vector<vector<bool>>>maps, int n, int m, int k) {
	for (int t = 0; t < k; t++) {
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < m; j++) {
				cout << maps[t][i][j];
			}
			cout << endl;
		}
		cout << endl;
	}
	cout << endl;
}
void Prints(vector<int>line, int n) {
	for (int i = 0; i < n; i++) {
		cout << line[i] << ",";
	}
	cout << endl;
}
void Prints(string str, int n) {
	for (int i = 0; i < n; i++) {
		cout << str[i] << ",";
	}
	cout << endl;
}

bool checkmaps(vector<vector<int>>maps, vector<vector<int>>anw, int n, int m) {
	bool bCheck = false;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if (maps[i][j] != anw[i][j]) {
				bCheck = true;
				i = n + 1;
				j = m + 1;
				continue;
			}
		}

	}
	return bCheck;

}
bool findstart(vector<vector<int>>maps, vector<vector<int>>anw, int n, int m, int) {
	bool bCheck = false;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if (maps[i][j] != anw[i][j]) {
				bCheck = true;
				i = n + 1;
				j = m + 1;
				continue;
			}
		}

	}
	return bCheck;

}

struct Data {
	Point p;
	int cnt;
	int sum;
};
vector<int>lists;
vector<bool>bCheck;
int n;
int del;
int maxs = 0;
int gcnt = 0;
bool bFind = false;
void dfs(int k, int cnt) {
	bCheck[k] = true;
	if (bFind==false) {
		bFind = true;
		gcnt++;
	}

	for (int i = 0; i < n; i++) {
		if (lists[i] == k&& bCheck[i]==false) {
			if (del != i) {
				dfs(i,cnt+1);
				
			}
		}
	}
	bFind = false;


}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	//트리 리프 노드 
	//자식의 개수가 0인 노드 
	//0
	
	cin >> n;
	int start;
	
	for (int i = 0; i < n; i++) {
		int tmp;
		cin >> tmp;
		
		bCheck.push_back(false);
		lists.push_back(tmp);
		if (tmp == -1) {
			start = i;
		}
	}
	
	cin >> del;
	if (del == start) {
		cout << 0;
		return 0;
	}
	dfs(start, 0);
	
	cout << gcnt;
	return 0;

}