Submission #9179

#	Time	Username	Problem	Language	Result	Execution time	Memory
9179		corea	Your life (kriii2_Y)	C++14	0 / 4	0 ms	3652 KiB

Y

#include <stdio.h>
#include <vector>
#include <queue>

using namespace std;

bool V[ 100003 ];

vector<int> data[ 100003 ];

priority_queue< pair<int, int> > pq;


int N, M;


int main() {
	scanf( "%d %d", &N, &M );

	while( M -- ) {
		int a, b;
		scanf( "%d %d", &a, &b );

		data[ a ].push_back( b );
	}

	pq.emplace( 0, 1 );

	for( int i = 0; i < N; i ++ ) {
		pair<int, int> now = pq.top();
		pq.pop();

		if( now.second == N ) {
			printf( "%d\n", - now.first );
			return 0;
		}
		if( V[ now.second ] ) {
			continue;
		}
		V[ now.second ] = true;
		
		for( auto &v : data[ now.second ] ) {
			if( V[ v ] ) {
				continue;
			}
			pq.emplace( now.first - 1, v );
		}
	}

	printf( "-1\n" );
	
	return 0;
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 3