Submission #1064676

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064676		Malix	Evacuation plan (IZhO18_plan)	C++14	0 / 100	681 ms	72876 KiB

plan

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef pair<int,int> pi;
typedef vector<pi> pii;
typedef tuple<int,int,int> tii;
typedef vector<ll> li;
typedef vector<li> lii;
 
#define REP(i,a,b) for(int i=a;i<b;i++)
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define LSOne(s) ((s)&(-s))
 
ll INF=1000000000000000010;
int inf=1e9+10;
ll M=1e9+7;

int n,m,k,q,t;
vector<vector<pair<int,ll>>> a,c;
pii ed;
vi b,p,vis,sa,se;
vector<ll> dist;
vector<vector<ll>> mn;
int sval=0,eval=0;
vii par;

void dfs(int x){
    sa[x]=sval++;
    for(auto u:c[x]){
        if(sa[u.F]!=-1)continue;
        par[u.F][0]=x;
        dfs(u.F);
    }
    se[x]=eval++;
}

bool ances(int x,int y){
    if(sa[x]>=sa[y]&&se[x]<=se[y])return 1;
    return 0;
}

ll solve(int x,int y){
    int z=y;
    ll ans=mn[y][0];
    for(int i=t-1;i>=0;i--)if(par[y][i]!=-1&&!ances(x,par[y][i])){
        ans=min(ans,mn[y][i]);
        y=par[y][i];
    }
    return min(ans,mn[y][0]);
}

int main() {   
    cin>>n>>m;
    a.resize(n);
    REP(i,0,m){
        int x,y;ll z;
        cin>>x>>y>>z;
        x--;y--;
        ed.PB({x,y});
        a[x].PB({y,z});
        a[y].PB({x,z});
    }
    cin>>k;
    b.resize(k);
    REP(i,0,k)cin>>b[i];
    REP(i,0,k)b[i]--;
    dist.resize(n,INF);
    priority_queue<pair<ll,int>,vector<pair<ll,int>>,greater<pair<ll,int>>> pq;
    REP(i,0,k){
        dist[b[i]]=0;
        pq.push({0,b[i]});
    }
    while(!pq.empty()){
        ll d=pq.top().F;
        int x=pq.top().S;
        pq.pop();
        if(d!=dist[x])continue;
        for(auto u:a[x]){
            if(dist[u.F]<=dist[x]+u.S)continue;
            dist[u.F]=dist[x]+u.S;
            pq.push({dist[u.F],u.F});
        }
    }
    c.resize(n);
    priority_queue<tuple<ll,int,int>> pq2;
    vis.resize(n,0);
    vis[0]=1;
    for(auto u:a[0])pq2.push({min(dist[0],dist[u.F]),0,u.F});
    while(!pq2.empty()){
        ll x=get<0>(pq2.top());
        int y=get<1>(pq2.top());
        int z=get<2>(pq2.top());
        pq2.pop();
        if(vis[z])continue;
        c[y].PB({z,x});
        c[z].PB({y,x});
        vis[z]=1;
        for(auto u:a[z])pq2.push({min(dist[z],dist[u.F]),z,u.F});
    }
    sa.resize(n,-1);se.resize(n,-1);
    t=log2(n)+1;
    par.resize(n,vi(t,-1));mn.resize(n,vector<ll>(t,INF));
    dfs(0);
    REP(i,0,n)if(par[i][0]!=-1)mn[i][0]=dist[par[i][0]];
    REP(j,1,t)REP(i,0,n)if(par[i][j-1]!=-1)par[i][j]=par[par[i][j-1]][j-1];
    REP(j,1,t)REP(i,0,n)if(par[i][j-1]!=-1)mn[i][j]=min(mn[i][j-1],mn[par[i][j-1]][j-1]);
    cin>>q;
    while(q--){
        int x,y;cin>>x>>y;
        x--;y--;
        ll ans=min(solve(x,y),solve(y,x));
        ans=min(ans,dist[x]);
        ans=min(ans,dist[y]);
        cout<<ans<<"\n";
    }
}

Compilation message (stderr)

plan.cpp: In function 'll solve(int, int)':
plan.cpp:49:9: warning: unused variable 'z' [-Wunused-variable]
   49 |     int z=y;
      |         ^

• Subtask 1: 0 / 10
• Subtask 2: 0 / 13
• Subtask 3: 0 / 12
• Subtask 4: 0 / 19
• Subtask 5: 0 / 46