Submission #1287843

#	Time	Username	Problem	Language	Result	Execution time	Memory
1287843		maxphast	Commuter Pass (JOI18_commuter_pass)	C++20	100 / 100	219 ms	26516 KiB

commuter_pass

/*
* @Author: MaxPhast
* @File:   test.cpp
* @Date:   2025-11-05 14:31:40
*/
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ii pair <int , int>
#define iii pair <int , ii>
#define iiii pair <ii , ii>
#define FOR(i , l , r) for(int i = (l) , _r = (r) ; i <= _r ; ++ i)
#define FORD(i , r , l) for(int i = (r) , _l = (l) ; i >= _l ; -- i)
#define ALL(vec) vec.begin() , vec.end()
#define UNI(vec) sort(ALL(vec)) , vec.erase(unique(ALL(vec)) , vec.end())
#define pb push_back
#define MASK(i) (1ll << i)
#define BIT(mask , i) ((mask >> i) & 1ll)
#define ON(mask , i) (mask | MASK(i))
#define OFF(mask , i) (mask & (~MASK(i)))
#define TURN(mask , i) (mask ^ MASK(i))
#define BP(mask) __builtin_popcountll(mask)
#define sqr(x) (1ll * (x) * (x))
#define fi first
#define se second
#define oo 1e18
#define time() cerr << " \n " << "Time : " << 1000.0 * clock() / CLOCKS_PER_SEC << "ms."
#define IO(TASK) if(fopen(#TASK".INP" , "r")){freopen(#TASK".INP" , "r" , stdin); freopen(#TASK".OUT" , "w" , stdout);}

template <class X , class Y>
    bool maxz(X &a , const Y b)
    {
        if(a < b)
        {
            a = b;
            return true;
        }
        return false;
    }
template <class X , class Y>
    bool minz(X &a , const Y b)
    {
        if(a > b)
        {
            a = b;
            return true;
        }
        return false;
    }

namespace MaxPhast
{

    const int N = 1e5 + 5;

    int n , m , S , T , U , V;
    int dist[N][2] , d[N][4];
    vector <ii> g[N];
    priority_queue <ii , vector <ii> , greater <ii>> pq;
    priority_queue <iii , vector <iii> , greater <iii>> q;

    void dijk(int s , int t)
    {
        FOR(i , 1 , n) dist[i][t] = oo;
        dist[s][t] = 0;
        pq.push({dist[s][t] , s});
        while(!pq.empty())
        {
            ii tmp = pq.top();
            pq.pop();
            if(tmp.fi > dist[tmp.se][t])
                continue;
            for(ii &v : g[tmp.se])
                if(minz(dist[v.fi][t] , dist[tmp.se][t] + v.se))
                    pq.push({dist[v.fi][t] , v.fi});
        }
    }

    void solve()
    {
        cin >> n >> m >> S >> T >> U >> V;

        FOR(i , 1 , m)
        {
            int u , v , w; cin >> u >> v >> w;
            g[u].pb({v , w});
            g[v].pb({u , w});
        }

        dijk(S , 0);
        dijk(T , 1);

        FOR(i , 1 , n)
            FOR(j , 0 , 3)
                d[i][j] = oo;

        d[U][0] = 0;
        q.push({d[U][0] , {U , 0}});

        while(!q.empty())
        {
            iii tmp = q.top();
            q.pop();

            if(tmp.fi > d[tmp.se.fi][tmp.se.se])
                continue;

            for(ii &v : g[tmp.se.fi])
            {
                if(tmp.se.se == 0)
                {
                    if(minz(d[v.fi][0] , d[tmp.se.fi][0] + v.se))
                        q.push({d[v.fi][0] , {v.fi , 0}});

                    if(dist[v.fi][0] + dist[tmp.se.fi][1] + v.se == dist[T][0])
                    {
                        if(minz(d[v.fi][1] , d[tmp.se.fi][0]))
                            q.push({d[v.fi][1] , {v.fi , 1}});
                    }

                    if(dist[v.fi][1] + dist[tmp.se.fi][0] + v.se == dist[T][0])
                    {
                        if(minz(d[v.fi][2] , d[tmp.se.fi][0]))
                            q.push({d[v.fi][2] , {v.fi , 2}});
                    }
                }

                if(tmp.se.se == 1)
                {
                    if(dist[v.fi][0] + dist[tmp.se.fi][1] + v.se == dist[T][0])
                    {
                        if(minz(d[v.fi][1] , d[tmp.se.fi][1]))
                            q.push({d[v.fi][1] , {v.fi , 1}});
                    }
                    else
                    {
                        if(minz(d[v.fi][3] , d[tmp.se.fi][1] + v.se))
                            q.push({d[v.fi][3] , {v.fi , 3}});
                    }
                }

                if(tmp.se.se == 2)
                {
                    if(dist[v.fi][1] + dist[tmp.se.fi][0] + v.se == dist[T][0])
                    {
                        if(minz(d[v.fi][2] , d[tmp.se.fi][2]))
                            q.push({d[v.fi][2] , {v.fi , 2}});
                    }
                    else
                    {
                        if(minz(d[v.fi][3] , d[tmp.se.fi][2] + v.se))
                            q.push({d[v.fi][3] , {v.fi , 3}});
                    }
                }

                if(tmp.se.se == 3)
                {
                    if(minz(d[v.fi][3] , d[tmp.se.fi][3] + v.se))
                        q.push({d[v.fi][3] , {v.fi , 3}});
                }
            }
        }

        cout << min({d[V][0] , d[V][1] , d[V][2] , d[V][3]});
    }

}

signed main()
{
    ios_base :: sync_with_stdio(false) ; cin.tie(nullptr) ; cout.tie(nullptr);
    IO(test);
    MaxPhast :: solve();
    time();
}
/*

*/

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:29:54: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 | #define IO(TASK) if(fopen(#TASK".INP" , "r")){freopen(#TASK".INP" , "r" , stdin); freopen(#TASK".OUT" , "w" , stdout);}
      |                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:173:5: note: in expansion of macro 'IO'
  173 |     IO(test);
      |     ^~
commuter_pass.cpp:29:90: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 | #define IO(TASK) if(fopen(#TASK".INP" , "r")){freopen(#TASK".INP" , "r" , stdin); freopen(#TASK".OUT" , "w" , stdout);}
      |                                                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:173:5: note: in expansion of macro 'IO'
  173 |     IO(test);
      |     ^~

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