Submission #230384

#	Time	Username	Problem	Language	Result	Execution time	Memory
230384		arnold518	Cities (BOI16_cities)	C++14	100 / 100	3106 ms	51368 KiB

cities

#include <bits/stdc++.h>
using namespace std;

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

const int MAXN = 1e5;
const ll INF = 1e18;

int N, M, K;
int A[10];
vector<pii> adj[MAXN+10];

ll dist[MAXN+10][40];

struct Queue
{
	int v; ll w;
	bool operator < (const Queue &p) const { return w>p.w; }
};

int main()
{
	int i, j, k;

	scanf("%d%d%d", &N, &K, &M);
	for(i=0; i<K; i++) scanf("%d", &A[i]);
	for(i=1; i<=M; i++)
	{
		int u, v, w;
		scanf("%d%d%d", &u, &v, &w);
		adj[u].push_back({v, w});
		adj[v].push_back({u, w});
	}

	for(i=1; i<=N; i++) for(j=1; j<(1<<K); j++) dist[i][j]=INF;
	for(i=0; i<K; i++) dist[A[i]][(1<<i)]=0;

	for(i=1; i<(1<<K); i++)
	{
		for(k=1; k<=N; k++)
		{
			for(j=i&(i-1); j; j=i&(j-1))
			{
				dist[k][i]=min(dist[k][j]+dist[k][i^j], dist[k][i]);
			}
		}

		priority_queue<Queue> PQ;
		for(k=1; k<=N; k++) PQ.push({k, dist[k][i]});
		while(!PQ.empty())
		{
			Queue now=PQ.top(); PQ.pop();
			if(now.w>dist[now.v][i]) continue;
			for(auto &nxt : adj[now.v])
			{
				if(dist[nxt.first][i]>now.w+nxt.second)
				{
					dist[nxt.first][i]=now.w+nxt.second;
					PQ.push({nxt.first, dist[nxt.first][i]});
				}
			}
		}
	}

	ll ans=INF;
	for(i=1; i<=N; i++) ans=min(ans, dist[i][(1<<K)-1]);
	printf("%lld\n", ans);
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:27:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d", &N, &K, &M);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
cities.cpp:28:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=0; i<K; i++) scanf("%d", &A[i]);
                     ~~~~~^~~~~~~~~~~~~
cities.cpp:32:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   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