Submission #946303

#	Time	Username	Problem	Language	Result	Execution time	Memory
946303		phoenix0423	Cities (BOI16_cities)	C++17	100 / 100	1802 ms	51632 KiB

cities

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
#pragma GCC optimize("Ofast", "unroll-loops")
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define int long long
#define lowbit(x) x&-x
const int maxn = 1e5 + 5;
const int INF = 1e18;
int dp[40][maxn];
int n, k, m;
vector<pll> adj[maxn];

signed main(void){
	fastio;
	cin>>n>>k>>m;
	vector<int> a(k);
	for(int i = 0; i < k; i++) cin>>a[i], a[i] --;
	for(int i = 0; i < m; i++){
		int a, b, w;
		cin>>a>>b>>w;
		a--, b--;
		adj[a].eb(b, w);
		adj[b].eb(a, w);
	}
	for(int i = 1; i < (1 << k); i++){
		for(int j = 0; j < n; j++) dp[i][j] = INF;
	}
	for(int i = 0; i < k; i++) dp[(1 << i)][a[i]] = 0;

	for(int mask = 0; mask < (1 << k); mask++){
		for(int i = 0; i < n; i++){
			for(int s = mask; s; s = (s - 1) & mask){
				dp[mask][i] = min(dp[mask][i], dp[s][i] + dp[mask ^ s][i]);
			}
		}
		priority_queue<pll, vector<pll>, greater<pll>> q;
		for(int i = 0; i < n; i++) q.push({dp[mask][i], i});
		while(!q.empty()){
			auto [d, pos] = q.top(); q.pop();
			if(dp[mask][pos] != d) continue;
			for(auto [x, w] : adj[pos]){
				if(dp[mask][x] > d + w){
					dp[mask][x] = d + w;
					q.push({dp[mask][x], x});
				}
			}
		}
	}
	int ans = INF;
	for(int i = 0; i < n; i++) ans = min(ans, dp[(1 << k) - 1][i]);
	cout<<ans<<"\n";
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26