Submission #544949

#	Time	Username	Problem	Language	Result	Execution time	Memory
544949		MilosMilutinovic	Cities (BOI16_cities)	C++14	100 / 100	2619 ms	42812 KiB

cities

#include<bits/stdc++.h>

#define fi first
#define se second
#define pb push_back
#define mp make_pair

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

template<typename T> bool chkmin(T&x,T y){return x<y?x=y,1:0;}
template<typename T> bool chkmax(T&x,T y){return x>y?x=y,1:0;}

const ll inf=(ll)1e18;
int n,k,m,id[100005];
ll dist[100005][1<<5];
vector<pii> g[100005];
priority_queue<pair<ll,int>> que;

void dijkstra(int mask){
	for(int i=1;i<=n;i++)if(dist[i][mask]!=inf)que.push(mp(-dist[i][mask],i));
	while(!que.empty()){
		ll d=-que.top().first;
		int u=que.top().second;
		que.pop();
		if(dist[u][mask]<d)continue;
		for(auto e:g[u]){
			int v=e.first,w=e.second;
			if(dist[v][mask]>dist[u][mask]+w){
				dist[v][mask]=dist[u][mask]+w;
				que.push(mp(-dist[v][mask],v));
			}
		}
	}
}

int main(){
	scanf("%d%d%d",&n,&k,&m);
	for(int i=1;i<=n;i++)id[i]=-1;
	for(int i=1;i<=n;i++)for(int j=0;j<(1<<k);j++)dist[i][j]=inf;
	for(int i=1;i<=k;i++){
		int x;scanf("%d",&x);
		id[x]=i-1; dist[x][1<<(i-1)]=0;
	}
	for(int i=1;i<=m;i++){
		int u,v,w;scanf("%d%d%d",&u,&v,&w);
		g[u].pb(mp(v,w)); g[v].pb(mp(u,w));
	}
	for(int mask=1;mask<(1<<k);mask++){
		if(__builtin_popcount(mask)>1){
			for(int s=((mask-1)&mask);s>0;s=((s-1)&mask)){
				for(int i=1;i<=n;i++)dist[i][mask]=min(dist[i][mask],dist[i][s]+dist[i][mask^s]);
			}
		}
		dijkstra(mask);
	}
	ll ans=inf;
	for(int i=1;i<=n;i++)ans=min(ans,dist[i][(1<<k)-1]);
	printf("%lld",ans);
	return 0;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:42:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |  scanf("%d%d%d",&n,&k,&m);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~
cities.cpp:46:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |   int x;scanf("%d",&x);
      |         ~~~~~^~~~~~~~~
cities.cpp:50:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |   int u,v,w;scanf("%d%d%d",&u,&v,&w);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~

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