Submission #253404

#	Time	Username	Problem	Language	Result	Execution time	Memory
253404		super_j6	Museum (CEOI17_museum)	C++14	80 / 100	3080 ms	784248 KiB

museum

#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>
#include <string.h>
using namespace std;
#define endl '\n'
#define ll long long
#define pi pair<int, int>
#define f first
#define s second
 
const int inf = 0x3f3f3f3f;
const int mxn = 10001;
int n, k, x;
int dp[mxn][mxn][2];
vector<pi> g[mxn];
 
void dfs(int c, int p){
	memset(dp[c], inf, sizeof(dp[c]));
	dp[c][1][0] = dp[c][1][1] = 0;
	for(pi i : g[c]){
		if(i.f == p) continue;
		dfs(i.f, c);
		for(int j = k; ~j; j--){
			int ret[2] = {inf, inf};
			for(int l = 0; l <= j; l++){
				ret[0] = min(ret[0], dp[c][j - l][0] + dp[i.f][l][0] + 2 * i.s);
				ret[1] = min(ret[1], dp[c][j - l][1] + dp[i.f][l][0] + 2 * i.s);
				ret[1] = min(ret[1], dp[c][j - l][0] + dp[i.f][l][1] + i.s);
			}
			for(int l = 0; l < 2; l++){
				dp[c][j][l] = min(dp[c][j][l], ret[l]);
			}
		}
	}/*
	cout << c + 1 << endl;
	for(int i = 0; i <= k; i++) cout << dp[c][i][0] << " " << dp[c][i][1] << " | ";
	cout << endl;
	*/
}
 
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> k >> x;
	x--;
	
	for(int i = 0; i < n - 1; i++){
		int u, v, w;
		cin >> u >> v >> w;
		u--, v--;
		g[u].push_back({v, w});
		g[v].push_back({u, w});
	}
	
	dfs(x, -1);
	
	cout << dp[x][k][1] << endl;
 
	return 0;
}

Compilation message (stderr)

museum.cpp:2:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("O3")
 
museum.cpp:3:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("unroll-loops")

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 35 / 35
• Subtask 4: 0 / 20