Submission #824196

#	Time	Username	Problem	Language	Result	Execution time	Memory
824196		LeVanThuc	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	4 ms	4308 KiB

commuter_pass

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
#define p(x,y) pair<ll,ll>(x,y)
#define BIT(i,x) ((x>>i)&1)
#define MASK(x) (1<<x)
#define ld long double
#define __builtin_popcount __builtin_popcountll
#define pll pair<ll,ll>
template<class T1,class T2>
bool maximize(T1 &x,const T2 &y)
{
    if(x<y)
    {
        x=y;
        return 1;
    }
    return 0;
}
template<class T1,class T2>
bool minimize(T1 &x,const T2 &y)
{
    if(x>y)
    {
        x=y;
        return 1;
    }
    return 0;
}
void online()
{
    std::ios_base::sync_with_stdio(0);
    cin.tie(0);
#ifndef ONLINE_JUDGE
    freopen("input.inp", "r", stdin);
    freopen("output.out","w", stdout);
#else
#endif
}
const ll N=1e5+10;
vector<pll> gr[N];
ll f[N],n,m,s,t,x,y,U[2*N],V[2*N],C[2*N],f1[N];
int main()
{
    online();
    cin>>n>>m>>s>>t>>x>>y;
    for(int i=1;i<=m;i++)
    {
        ll u,v,c;
        cin>>u>>v>>c;
        U[i]=u;
        V[i]=v;
        C[i]=c;
        gr[u].emplace_back(v,c);
        gr[v].emplace_back(u,c);
    }
    memset(f,0x3f,sizeof f);
    f[s]=0;
    priority_queue<pll,vector<pll>,greater<pll> > qq;
    qq.emplace(0,s);
    while(!qq.empty())
    {
        auto [d,u]=qq.top();
        qq.pop();
        if(f[u]!=d) continue;
        for(auto [v,c]:gr[u])
        {
            if(minimize(f[v],d+c)) qq.emplace(f[v],v);
        }
    }
    memset(f1,0x3f,sizeof f1);
    f1[t]=0;
    qq.emplace(0,t);
    while(!qq.empty())
    {
        auto [d,u]=qq.top();
        qq.pop();
        if(f1[u]!=d) continue;
        for(auto [v,c]:gr[u])
        {
            if(minimize(f1[v],d+c)) qq.emplace(f1[v],v);
        }
    }
    for(int i=1;i<=m;i++)
    {
        if(f[U[i]]+C[i]+f1[V[i]]==f[t])
        {
            if(f[U[i]]<f[V[i]])
            gr[U[i]].emplace_back(V[i],0);
            else
            gr[V[i]].emplace_back(U[i],0);
        }
    }
    memset(f,0x3f,sizeof f);
    f[x]=0;
    qq.emplace(0,x);
    while(!qq.empty())
    {
        auto [d,u]=qq.top();
        qq.pop();
        if(f[u]!=d) continue;
        for(auto [v,c]:gr[u])
        {
            if(minimize(f[v],d+c)) qq.emplace(f[v],v);
        }
    }
    ll ans=f[y];
    memset(f,0x3f,sizeof f);
    f[y]=0;
    qq.emplace(0,y);
    while(!qq.empty())
    {
        auto [d,u]=qq.top();
        qq.pop();
        if(f[u]!=d) continue;
        for(auto [v,c]:gr[u])
        {
            if(minimize(f[v],d+c)) qq.emplace(f[v],v);
        }
    }
    minimize(ans,f[x]);
    cout<<ans;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void online()':
commuter_pass.cpp:37:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     freopen("input.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:38:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |     freopen("output.out","w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45