Submission #974470

#	Time	Username	Problem	Language	Result	Execution time	Memory
974470		KasymK	Cat in a tree (BOI17_catinatree)	C++17	11 / 100	1066 ms	3920 KiB

catinatree

#include "bits/stdc++.h"

using namespace std;

const int N = 1e5 + 5;

vector<int> adj[N], vis;

int n, d;
int mx = INT_MIN;

int marked[N], dis[N], vis1[N];


int poz = 0;

int in_yakyn (int x) {
//	if (poz) {
//		cout <<"--> " << x;
//		exit(0);
//	}
	queue <int> q;
	for (int i = 0; i < n; ++i) vis1[i] = dis[i] = 0;
	q.push(x);
	vis1[x] = 1;	
	while (!q.empty()) {
		int to = q.front();
//		if (poz == 1) {
//			cout << "ll-> " << to << "\n";
//		}
		q.pop();
		for (int i : adj[to]) {
			if (vis1[i]) continue;
			dis[i] = dis[to] + 1;
			q.push(i);
			vis1[i] = 1;
				
			if (vis[i]) {
//				if (poz) {
//					cout << " men " << i << " " << x << " " << dis[i] << "\n";
////					exit(0);	
//					
//				}
				return dis[i];  
			}
		}
	}
	assert (1 == -1);
}


bool barla() {
    int cnt = count(vis.begin(), vis.end(), 1);
    if(cnt <= 1)
        return true;
    if (vis[0] == 0 and vis[1] == 0 and vis[2] == 1 and vis[3] == 1) {
    	poz = 1;
//		cout << " kk --> " << in_yakyn (3);
//		 << " " << in_yakyn (2);
//    	exit(0);
	}
   	for (int i = 0; i < n; ++i) {
   		if (vis[i]) {
   			if (in_yakyn(i) < d) return 0; 
		}	
	}
	return 1;
}

int sana () {
	int ret = 0;
	for (int i = 0; i < n; ++i) {
		if (vis[i]) ret++;
	}
	return ret;
}

void f(int x){
    if(x == n){
        if(barla())
            mx = max(mx, sana());
        return;
    }
    for(int i = 0; i <= 1; ++i){
        vis[x] = i;
        f(x + 1);
    }
}

int main() { 
//	freopen ("input.txt", "r", stdin);
    scanf("%d%d", &n, &d);
    for(int i = 1; i <= n - 1; ++i) {
        int a;
        scanf("%d", &a);
        adj[a].push_back(i);
        adj[i].push_back(a);
    }
    vis.resize(n);
    f(0);
    printf("%d\n", mx);
    return 0;
}

Compilation message (stderr)

catinatree.cpp: In function 'int main()':
catinatree.cpp:92:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |     scanf("%d%d", &n, &d);
      |     ~~~~~^~~~~~~~~~~~~~~~
catinatree.cpp:95:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |         scanf("%d", &a);
      |         ~~~~~^~~~~~~~~~

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