Submission #925838

#	Time	Username	Problem	Language	Result	Execution time	Memory
925838		Cutebol	Commuter Pass (JOI18_commuter_pass)	C++17	15 / 100	913 ms	37776 KiB

commuter_pass

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;
 
bool YES(bool f){ if(f) cout << "Yes\n" ; else cout << "No\n" ; return f ; }
void YES(){YES(1);}
void NO(){YES(0);}
void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
//#define ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
#define ios ios_base::sync_with_stdio(0) ; cin.tie(0) ; cout.tie(0);
#define int long long
#define ld long double
#define pii pair <int , int>
#define all(x) x.begin() , x.end()
#define ff first
#define ss second
#define endl '\n'
 
const int N = 2e5 + 5 ;
const int inf = 1e16 ;
const int mod = 1e9 + 8 ;
const double eps = 1e-8 ;
 
int binpow( int a , int b ){
  if ( b == 0 ) return 1 ;
  int x = binpow ( a , b/2 ) ;
  if ( !(b%2) ) return (x*x) ;
  return (x*x*a) ;
}
template <class T>
bool chmax( T& x , const T& y ){
  bool f = 0 ;
  if ( x < y ) x = y , f = 1 ;
  return f ;
}
template <class T>
bool chmin( T &x , const T &y ){
  bool f = 0 ;
  if ( x > y ) x = y , f = 1 ;
  return f ;
}
 
//code
 
int n , m , a , b , c , d , ans ;
vector <pii> g[N] ;
int dis[N][2] , dp[2][N] , ds[N] ;
bool vis[N] ;

void dijkstra( int s , int f ){
	memset( vis , 0 , sizeof(vis)) ;
	set <pii> st ;
	st.insert({0,s}) ;
	while ( st.size() ){
		int v = st.begin()->ss ;
		int d = st.begin()->ff ;
		st.erase(st.begin()) ;
		if (!vis[v]){
			vis[v] = 1 ;
			dis[v][f] = d ;
			for ( auto to : g[v] ) st.insert({d+to.ss,to.ff}) ;
		}
	}
	
}

void calc ( int a , int b ){
	memset ( dp[0] , 0x3F , sizeof(dp[0]) ) ;
	memset ( dp[1] , 0x3F , sizeof(dp[1]) ) ;
	memset ( vis , 0 , sizeof(vis) ) ;
	set <pair < int , pii>> st ;
	st.insert({0,{a,0}}) ;
	while (st.size()){
		int v = st.begin()->ss.ff ;
		int d = st.begin()->ff ;
		int p = st.begin()->ss.ss ;
		st.erase(st.begin()) ;
		if ( !vis[v] ){
			vis[v] = 1 ;
			ds[v] = d ;
			dp[0][v] = min ( dp[0][p] , dis[v][0] ) ;
			dp[1][v] = min ( dp[1][p] , dis[v][1] ) ;
			for ( auto to : g[v] ) st.insert({d+to.ss,{to.ff,v}}) ;
		}
		else if ( d == ds[v] ){
			if ( dp[0][v] + dp[1][v] > min ( dp[0][p] , dis[v][0] ) + min ( dp[1][p] , dis[v][1] ) ){
				dp[0][v] = min ( dp[0][p] , dis[v][0] ) ;
				dp[1][v] = min ( dp[1][0] , dis[v][1] ) ;
			}
		}
	}
	chmin ( ans , dp[0][b] + dp[1][b] ) ;
}

void solve(){
	
	cin >> n >> m >> a >> b >> c >> d ;
	for ( int i = 0 ; i < m ; i ++ ){
		int x , y , c ; cin >> x >> y >> c ;
		g[x].push_back({y,c}) ;
		g[y].push_back({x,c}) ;
	}
	dijkstra( c , 0 ) ;
	dijkstra( d , 1 ) ;
	ans = dis[d][0] ;
	calc(a,b) ;
	calc(b,a) ;
	cout << ans ;
}
 
signed main(){
    //ios ;
	int t = 1 ;
	//cin >> t ;
	while ( t -- ) solve() ;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void fopn(std::string)':
commuter_pass.cpp:10:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:10:72: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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