Submission #786843

#	Time	Username	Problem	Language	Result	Execution time	Memory
786843		winter0101	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	217 ms	23748 KiB

commuter_pass

#include<bits/stdc++.h>
using namespace std;
#define all(fl) fl.begin(),fl.end()
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define lb lower_bound
#define ub upper_bound
#define sz(a) (int)a.size()
#define pii pair<int,int>
#define pli pair<long long,int>
#define gcd __gcd
#define lcm(x,y) x*y/__gcd(x,y)
#define pil pair<int,long long>
const int maxn=1e5+9;
const long long inf=2e15;
vector<pil>a[maxn];
int n,m;
struct cus{
int u;
long long w;
bool operator< (const cus &p)const {
return w>p.w;
}
};
vector<long long> sp(int u1){
vector<long long>dis;
dis.resize(n+1);
for1(i,1,n)dis[i]=inf;
dis[u1]=0;
vector<bool>visit;
visit.resize(n+1);
priority_queue<cus>c;
c.push({u1,0});
while (!c.empty()){
    auto u=c.top();
    c.pop();
    if (visit[u.u])continue;
    visit[u.u]=1;
    for (auto v:a[u.u]){
        long long newval=v.se+u.w;
        if (newval<dis[v.fi]){
            dis[v.fi]=newval;
            c.push({v.fi,newval});
        }
    }
}
return dis;
}
vector<long long>disu,disv;
long long f[maxn][2][2];
int s,t,u1,v1;
long long solve(){
vector<long long>dis;
dis.resize(n+1);
for1(i,1,n)dis[i]=inf;
for1(i,1,n){
for1(j,0,1){
for1(k,0,1){
f[i][j][k]=inf;
}
}
f[i][1][0]=disu[i];
f[i][1][1]=disu[i]+disv[i];
f[i][0][1]=disv[i];
}
dis[s]=0;
vector<bool>visit;
visit.resize(n+1);
priority_queue<cus>c;
c.push({s,0});
while (!c.empty()){
    auto u=c.top();
    c.pop();
    //if (u.u==2)cout<<u.w<<'\n';
    //cout<<u.u<<'\n';
    if (visit[u.u])continue;
    visit[u.u]=1;
    f[u.u][1][0]=min(f[u.u][1][0],disu[u.u]);
    f[u.u][0][1]=min(f[u.u][0][1],disv[u.u]);
    f[u.u][1][1]=min({f[u.u][1][1],f[u.u][1][0]+disv[u.u],f[u.u][0][1]+disu[u.u]});
    //if (u.u==2)cout<<u.w<<'\n';
    for (auto v:a[u.u]){
        long long newval=v.se+u.w;
        if (newval<dis[v.fi]){
            dis[v.fi]=newval;
            c.push({v.fi,newval});
            f[v.fi][1][0]=f[u.u][1][0];
            f[v.fi][1][1]=f[u.u][1][1];
            f[v.fi][0][1]=f[u.u][0][1];
        }
        else if (newval==dis[v.fi]){
            f[v.fi][1][0]=min(f[v.fi][1][0],f[u.u][1][0]);
            f[v.fi][1][1]=min(f[v.fi][1][1],f[u.u][1][1]);
            f[v.fi][0][1]=min(f[v.fi][0][1],f[u.u][0][1]);
        }
    }
}
return f[t][1][1];
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen("temp.INP","r",stdin);
    //freopen("temp.OUT","w",stdout);
    cin>>n>>m;
    cin>>s>>t>>u1>>v1;
    for1(i,1,m){
    int u,v;
    long long w;
    cin>>u>>v>>w;
    a[u].pb({v,w});
    a[v].pb({u,w});
    }
    disu=sp(u1),disv=sp(v1);
    cout<<min(solve(),disu[v1]);
    //solve();
    //cout<<f[1][0][1];
}

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 45 / 45