Submission #1239356

#	Time	Username	Problem	Language	Result	Execution time	Memory
1239356		thunopro	Commuter Pass (JOI18_commuter_pass)	C++20	24 / 100	25 ms	1344 KiB

commuter_pass

#include<bits/stdc++.h>
using namespace std ; 
#define maxn 309
#define ll long long 
#define pb push_back 
#define fi first 
#define se second 
#define left id<<1
#define right id<<1|1 
#define re exit(0); 
#define _lower(x) lower_bound(v.begin(),v.end(),x)-v.begin()+1 
#define TIME ( 1.0*clock() / CLOCKS_PER_SEC )
#define CEIL(a,b) (a/b + (a%b!=0))
const int mod = 1e9+7 ;
const int INF = 1e9 ; 

typedef vector<int> vi ; 
typedef pair<int,int> pii ; 
typedef vector<pii> vii ; 

template < typename T > void chkmin ( T &a , T b ) { if ( a > b ) a = b ; } 
template < typename T > void chkmax ( T &a , T b ) { if ( a < b ) a = b ; } 

void add ( int &a , int b ) 
{
    a += b ; 
    if ( a >= mod ) a -= mod ; 
    if ( a < 0 ) a += mod ; 
}

void rf () 
{
#ifndef ONLINE_JUDGE
freopen("bai1.inp","r",stdin);
freopen ("bai1.out","w",stdout) ;
#endif
}

int _pow ( int a , int n ) 
{
    if ( n == 0 ) return 1 ; 
    int res = _pow (a,n/2) ; 
    if ( n % 2 ) return 1ll*res*res%mod*a%mod ; 
    else return 1ll*res*res%mod ; 
}

int n ,m ; 
vi adjList [maxn] ; 
int S,T,U,V ; 
ll d [maxn][maxn] ; 

int main () 
{
    ios_base::sync_with_stdio(0); 
    cin.tie(0);cout.tie(0); 
    // rf () ;
    cin >> n >> m ; 
    cin >> S >> T >> U >> V ; 
    memset (d,0x3f,sizeof d) ; 
    for ( int i = 1 ; i <= n ; i ++ ) d[i][i] = 0 ; 
    for ( int i = 1 ; i <= m ; i ++ ) 
    {
        int u , v , w ; cin >> u >> v >> w ; 
        chkmin (d[u][v],1ll*w) ; 
        chkmin (d[v][u],1ll*w) ; 
    }
    for ( int k = 1 ; k <= n ; k ++ ) 
    {
        for ( int i = 1 ; i <= n ; i ++ ) 
        {
            for ( int j = 1 ; j <= n ; j ++ ) 
            {
                chkmin (d[i][j],d[i][k]+d[k][j]) ; 
            }
        }
    }

    ll res = d[U][V] ; 

    for ( int c1 = 1 ; c1 <= n ; c1 ++ ) for ( int c2 = 1 ; c2 <= n ; c2 ++ ) 
    {
        if ( d[S][c1] + d[c1][c2] + d[c2][T] == d[S][T] ) 
        {
            chkmin (res,min(d[c1][U]+d[c2][V],d[c1][V]+d[c2][U])) ; 
            
        }
    }

    cout << res ; 
    return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void rf()':
commuter_pass.cpp:34:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 | freopen("bai1.inp","r",stdin);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:35:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 | freopen ("bai1.out","w",stdout) ;
      | ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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