Submission #1093999

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093999		doducanh	Evacuation plan (IZhO18_plan)	C++14	100 / 100	590 ms	59416 KiB

plan

///breaker
///every second counts
#include<bits/stdc++.h>
using namespace std;

struct duongdi{
    int u,w;
    bool operator<(const duongdi&d2)const{
        return w > d2.w;
    }
};
struct edge
{
    int u,v,w;
    bool operator<(const edge&b)const{
        return w>b.w;
    }
};
const int maxn=1e5+7;
edge e[5*maxn];
vector<pair<int, int>>adj1[maxn],adj2[maxn];
int d[maxn],r[maxn],p[maxn][25], dp[maxn][25];
int h[maxn];
priority_queue<duongdi>q;
int sz[maxn];
int Find(int u){
    return ((u==r[u])?u:r[u]=Find(r[u]));
}
void dfs(int u, int pa){
    for(auto[v,w]:adj2[u]){
        if(v == pa) continue;
        p[v][0] = u;
        dp[v][0] = w;
        h[v]=h[u]+1;
        dfs(v, u);
    }
}
int lca(int u, int v){
    if(h[u]<h[v])swap(u, v);
    int diff=h[u]-h[v];
    int mn=1e9+7;
    for(int i=20;i>=0;i--)if((diff>>i)&1){
        mn=min(mn,dp[u][i]);
        u=p[u][i];
    }
    if(u == v) return mn;
    for(int i = 20; i>=0; --i){
        if(p[u][i]!=p[v][i]){
            mn=min({mn, dp[u][i], dp[v][i]});
            u=p[u][i];
            v=p[v][i];
        }
    }
    return min({mn,dp[u][0],dp[v][0]});
}

int main(){
//    freopen("walk.inp","r",stdin);
//    freopen("walk.out","w",stdout);
//    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int n,m,k,t;
    cin>>n>>m;
    for(int i=0;i<=20;i++){
        for(int j=1;j<=n;j++){
            dp[j][i]=1e9+7;
        }
    }
    for(int i=0;i<m;i++){
        int u,v,w;
        cin>>u>>v>>w;
        adj1[u].push_back({v, w});
        adj1[v].push_back({u, w});
        e[i].u=u;
        e[i].v=v;
    }
    for(int i = 1; i<=n; ++i)d[i] = 1e9;
    for(int i = 1; i<=n; ++i){
        r[i] = i;
        sz[i]=1;
    }
    cin>>k;
    for(int i = 1; i<=k; ++i){
        int u;
        cin>>u;
        d[u]=0;
        q.push({u, d[u]});
    }
    while(!q.empty()){
        int u=q.top().u;
        int du=q.top().w;
        q.pop();
        if(d[u]<du)continue;
        for(auto [v,w]:adj1[u]){
            if(d[v]>du+w){
                d[v]=du+w;
                q.push({v, d[v]});
            }
        }
    }
    for(int i=0;i<m;i++){
        e[i].w=min(d[e[i].u],d[e[i].v]);
    }
    sort(e,e+m);
    for(int i=0;i<m;i++){
        int u=e[i].u,v=e[i].v,w=e[i].w;
        if(Find(u)!=Find(v)){
            u=Find(u);
            v=Find(v);
            adj2[u].push_back({v, w});
            adj2[v].push_back({u, w});
            if(sz[u]<sz[v])swap(u,v);
            sz[u]+=sz[v];
            r[v]=u;
        }
    }
    dfs(1,0);
    for(int j = 1; j<=20; ++j){
		for(int i = 1; i<=n; ++i){
			p[i][j]=p[p[i][j-1]][j-1];
			dp[i][j] = min(dp[i][j-1], dp[p[i][j-1]][j-1]);
		}
	}
	cin>>t;
    while(t--){
        int u,v;
        cin>>u>>v;
        cout<<lca(u, v)<<"\n";
    }
    return 0;
}

Compilation message (stderr)

plan.cpp: In function 'void dfs(int, int)':
plan.cpp:30:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   30 |     for(auto[v,w]:adj2[u]){
      |             ^
plan.cpp: In function 'int main()':
plan.cpp:93:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   93 |         for(auto [v,w]:adj1[u]){
      |                  ^

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46