Submission #673373

#	Time	Username	Problem	Language	Result	Execution time	Memory
673373		viwlesxq	Biochips (IZhO12_biochips)	C++17	100 / 100	287 ms	401764 KiB

biochips

#include <bits/stdc++.h>
using namespace std;
 
using ll = int64_t;
using str = string;
 
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)x.size()
 
const int N = 2e5 + 5, M = 5e2 + 5, inf = 1e9 + 7;
vector <int> g[N];
int dp[N][M], x[N], timer, tin[N], arr[N], n, m, p;
 
void dfs(int v) {
	int in = timer;
	for (int to : g[v]) dfs(to);
	tin[timer] = in;
	arr[timer] = x[v];
	timer++;
}
 
signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> n >> m;
	int root = -1;
	timer = 1;
	for (int i = 1; i <= n; i++) {
		cin >> p >> x[i];
		if (!p) root = i;
		g[p].pb(i);
	}
	dfs(root);
	for (int i = 0; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			dp[i][j] = -inf;
		}
	}
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			dp[i][j] = max(dp[i - 1][j], dp[tin[i] - 1][j - 1] + arr[i]);
		}
	}
	cout << dp[n][m];
}

• Subtask 1: 100 / 100