Submission #492874

#	Time	Username	Problem	Language	Result	Execution time	Memory
492874		LastRonin	Cities (BOI16_cities)	C++14	100 / 100	3540 ms	47944 KiB

cities

#pragma GCC optimize("O3")
#pragma GCC target("popcnt")
#include <bits/stdc++.h>
#define pb push_back
#define ll long long
#define ull unsigned long long
#define mp make_pair
#define si short int
#define speed ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define pill pair<ll,ll>
#define f first
#define s second
#define pilc pair<ll,char>
#define all(a) (a).begin(),(a).end()
#define rep(s,e,step) for(int i = (s); i < (e) ; i += step)
#define vrep(s,e,step) for(int j = (s); j < (e) ; j += step)
#define ex exit(0) 
#define triple pair<pill, ll>
#define pinode pair<node*, node*>
#define quadra pair<pill, pill>
#define ld double
#define pild pair<double,double>
using namespace std;
    
const ll N = 1e5 + 11;
const ll M = 32;
const ll mod = 998244353;
   
mt19937_64 bruh(chrono::steady_clock::now().time_since_epoch().count());
 
ll n, m, k;
ll dp[N][M];
bool was[N][M];
vector<pill> g[N];  
vector<int> prec[M];
ll x[N];
 
int main() {                                                       
	speed;
	cin >> n >> k >> m;
	for(int i = 0; i < k; i++)	
		cin >> x[i];
	for(int i = 1; i < (1<<k); i++) {
		for(int j = i + 1; j < (1<<k); j++)
			if(!(i&j)) {
				prec[i].pb(j), prec[j].pb(i);
			}
	}
	for(int i = 1; i <= m; i++) {
		ll a, b, c;
		cin >> a >> b >> c;
		g[a].pb(mp(b, c));
		g[b].pb(mp(a, c));
	}
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j < (1<<k); j++)
			dp[i][j] = 1e17; 
	}
	for(int i = 0; i < k; i++) {         
		dp[x[i]][1<<i] = 0;
	}
	for(int i = 0; i < (1<<k); i++) {
		priority_queue<pair<ll, int>> q;
		for(int j = 1; j <= n; j++)
			q.push(mp(-dp[j][i], j));					
		while(q.size()) {
			ll v = (q.top()).s;
			q.pop();
			if(was[v][i])continue;			
			was[v][i] = 1;
			for(auto u : g[v]) {
				if(dp[u.f][i] > dp[v][i] + u.s) {
					dp[u.f][i] = dp[v][i] + u.s;
					q.push(mp(-dp[u.f][i], u.f));					
				}
			}
		}
		for(int v = 1; v <= n; v++) {
		    for(auto u : g[v]) {
				for(auto msk : prec[i]) {
					if(dp[u.f][msk|i] > dp[u.f][msk] + u.s + dp[v][i]) {	
						dp[u.f][msk|i] = dp[u.f][msk] + u.s + dp[v][i];
					}
				}
			}
		}
	}

	ll ans = 1e17;
	for(int i = 1; i <= n; i++)
		ans = min(ans, dp[i][(1<<k) - 1]);
	cout << ans;
}   
  
/*
5 3 1
1 2 4 7 11
5 7 10
1 3 2
 
*/

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