Submission #913972

#	Time	Username	Problem	Language	Result	Execution time	Memory
913972		trashaccount	Biochips (IZhO12_biochips)	C++17	90 / 100	198 ms	405528 KiB

biochips

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

int N, M, p[200005], x[200005], rt;
vector <int> son[200005];
int timer = 0, tin[200005], tout[200005], tour[200005], dp[200005][505];

void dfs(int u){
	tin[u] = ++timer;
	tour[timer] = u;
	for (int v : son[u]){
		dfs(v);
	}
	tout[u] = timer;
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	cin >> N >> M;
	for (int i = 1; i <= N; i++){
		cin >> p[i] >> x[i];
		if (!p[i]) rt = i;
		son[p[i]].push_back(i);
	}
	dfs(rt);
	for (int i = 1; i <= M; i++) dp[N+1][i] = -1e9;
	for (int i = N; i >= 1; i--){
		int u = tour[i];
		for (int j = 1; j <= M; j++)
			dp[i][j] = max(dp[tout[u]+1][j-1]+x[u], dp[i+1][j]);
	}
	cout << dp[1][M];
	return 0;
}

• Subtask 1: 90 / 100