Submission #970022

#	Time	Username	Problem	Language	Result	Execution time	Memory
970022		dubabuba	Cat in a tree (BOI17_catinatree)	C++14	100 / 100	95 ms	23376 KiB

catinatree

#include <bits/stdc++.h>
using namespace std;

typedef pair<int, int> pii;
#define ff first
#define ss second
#define MP make_pair

template<typename T> void ono_min(T &MIN, T CMP) { if(MIN > CMP) MIN = CMP; }
template<typename T> void ono_max(T &MAX, T CMP) { if(MAX < CMP) MAX = CMP; }

const int inf = 1e9 + 10;
const int mxn = 2e5 + 10;
int dis[mxn], dp[mxn];
vector<int> adj[mxn];

int n, d, ans;
void dfs(int u, int p = 0) {
	int mx = inf, cnt = 0;
	for(int v : adj[u]) {
		if(v == p) continue;
		dfs(v, u);

		if(mx + dis[v] >= d) {
			cnt += dp[v];
			ono_min(mx, dis[v]);
		} else {
			cnt += dp[v] - 1;
			ono_max(mx, dis[v]);
		}
	}

	if(mx >= d) {
		dis[u] = 1;
		dp[u] = cnt + 1;
	} else {
		dis[u] = mx + 1;
		dp[u] = cnt;
	}
	ono_max(ans, dp[u]);
}

int main() {
	cin >> n >> d;
	for(int i = 1, j; i < n; i++) {
		cin >> j;
		adj[i].push_back(j);
		adj[j].push_back(i);
	}

	dfs(0);
	cout << ans << endl;
	return 0;
}

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