Submission #1245786

#	Time	Username	Problem	Language	Result	Execution time	Memory
1245786		BJoozz	Cities (BOI16_cities)	C++20	0 / 100	6090 ms	38676 KiB

cities

#include <bits/stdc++.h>
#define ii pair<int, int>
#define fi first
#define se second
#define inf 0x3f3f3f3f3f3f3f3f
using namespace std;
using ll = long long;
const ll mod=1e9+7;
const int nx=1e5+5;
int n, m, k, a[nx], id[nx];
vector<ii> adj[nx];
ll dp[nx][32], ans=inf;
priority_queue<tuple<ll, int, int>> q;
int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin>>n>>k>>m;
    memset(id, -1, sizeof(id));
    for(int i = 0; i < k; i++)
        cin>>a[i], id[a[i]]=i;
    while(m--)
    {
        int u, v, w;
        cin>>u>>v>>w;
        adj[u].emplace_back(v, w);
        adj[v].emplace_back(u, w);
    }
    memset(dp, 0x3f, sizeof(dp));
    for(int i = 1; i <= n; i++)
    {
        int mask=(id[i]==-1)?0:(1<<id[i]);
        dp[i][mask]=0;
        q.push({0, i, mask});
    }
    while(q.size())
    {
        ll dis;
        int u, mask;
        tie(dis, u, mask)=q.top();
        if(mask==(1<<k)-1) break;
        q.pop();
        if(dp[u][mask]!=dis) continue;
        for(auto it:adj[u])
        {
            int nxt=mask|((id[it.fi]==-1)?0:(1<<id[it.fi]));
            if(dp[it.fi][nxt]>dp[u][mask]+it.se)
                dp[it.fi][nxt]=dp[u][mask]+it.se, q.push({dp[it.fi][nxt], it.fi, nxt});
        }
        int rev=((1<<k)-1)^mask;
        for(int m1 = rev; m1 > 0; m1=(m1-1)&rev)
        {
            int nxt=mask|m1;
            if(dp[u][nxt]>dp[u][mask]+dp[u][m1])
                dp[u][nxt]=dp[u][mask]+dp[u][m1], q.push({dp[u][nxt], u, nxt});
        }
    }
    for(int i = 1; i <= n; i++)
        ans=min(ans, dp[i][(1<<k)-1]);
    cout<<ans;
}

• Subtask 1: 0 / 22
• Subtask 2: 0 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 26