Submission #975139

#	Time	Username	Problem	Language	Result	Execution time	Memory
975139		Halym2007	Cat in a tree (BOI17_catinatree)	C++17	0 / 100	1 ms	2908 KiB

catinatree

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ff first
#define ss second
#define sz size()
const int N = 1e5 + 5;

int mark[N], n, d, x, vis[N];
vector <int> v[N];
void solve (int x, int pr, int dis) {
	if (dis >= d) {
		mark[x] = 1;
		dis = 0;
	}
	for (int i : v[x]) {
		if (i == pr) continue;
		solve (i, x, dis + 1);
	}
}

int dis[N];

int main () {
//	freopen ("input.txt", "r", stdin);	
	cin >> n >> d;
	for (int i = 1; i < n; ++i) {
		int x;
		cin >> x;
		v[x].pb (i);
		v[i].pb (x);
	}
	
	queue <int> q;
	q.push (0);
	vis[0] = 1;
	while (!q.empty()) {
		int x = q.front();
		q.pop();
		for (int i : v[x]) {
			if (vis[i]) continue;
			q.push (i);
			dis[i] = dis[x] + 1;
			vis[i] = 1;
		}
	}
	
	int node = 0;
	for (int i = 0; i < n; ++i) {
		if (dis[node] < dis[i]) {
			node = i;
		}
	}
	solve (node, -1, d);
	int ret = 0;
	for (int i = 0; i < n; ++i) {
		ret += mark[i] == 1;
	}
	cout << ret;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 40
• Subtask 3: 0 / 49