c_cpp 3767-I_Wanna_Go_Home.cpp

Posted 2021-05-14

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <vector>
#include <queue>
#include <cstring>
using namespace std;

#define MAXN 610

struct EDGE {
  int a, b, c;
};

EDGE edge[ 10010 ];
vector< int > vertex[ MAXN ];
int cost[ MAXN ][ MAXN ];
int camp[ MAXN ], dist[ MAXN ];
bool visit[ MAXN ];
int n, e;

int dijkstra( int st, int ed ) {
	typedef pair< int, int > NODE;
	priority_queue< NODE, vector< NODE >, greater< NODE > > PQ;
	memset( visit, 0, sizeof( visit ) );
	memset( dist, 63, sizeof( dist ) );
	dist[ st ] = 0;
	PQ.push( pair< int, int >( dist[ st ], st ) );

	while ( !PQ.empty() ) {
		int now = PQ.top().second;
		PQ.pop();
		visit[ now ] = 1;
		for ( int i = 0; i < vertex[ now ].size(); ++i ) {
			int next = vertex[ now ][ i ];
			if ( !visit[ next ] && dist[ now ] + cost[ now ][ next ] < dist[ next ] ) {
				dist[ next ] = dist[ now ] + cost[ now ][ next ];
				PQ.push( pair< int, int >( dist[ next ], next ) );
			}
		}
	}
	return dist[ ed ] == dist[ 0 ] ? -1 : dist[ ed ];
}

int main() {

	while ( ~scanf( "%d", &n ) && n ) {
		
		scanf( "%d", &e );
		for ( int i = 1; i <= n; ++i )
			vertex[ i ].clear();
		int a, b, c;
		for ( int i = 0; i < e; ++i )
			scanf( "%d %d %d", &edge[ i ].a, &edge[ i ].b, &edge[ i ].c );

		for ( int i = 1; i <= n; ++i ) {
			scanf( "%d", &c );
			camp[ i ] = c;
		}

		for ( int i = 0; i < e; ++i ) {
			if ( camp[ edge[ i ].a ] == camp[ edge[ i ].b ] ) {
				cost[ edge[ i ].a ][ edge[ i ].b ] = cost[ edge[ i ].b ][ edge[ i ].a ] = edge[ i ].c;
				vertex[ edge[ i ].a ].push_back( edge[ i ].b ), vertex[ edge[ i ].b ].push_back( edge[ i ].a );
			}
			else if ( camp[ edge[ i ].a ] == 1 )
				cost[ edge[ i ].a ][ edge[ i ].b ] = edge[ i ].c, vertex[ edge[ i ].a ].push_back( edge[ i ].b );
			else
				cost[ edge[ i ].b ][ edge[ i ].a ] = edge[ i ].c, vertex[ edge[ i ].b ].push_back( edge[ i ].a );
		}
		printf( "%d\n", dijkstra( 1, 2 ) );
	}

	return 0;
}