//By Lin
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int		ans,n,k,t,g,h; 
int		main()
{
	scanf("%d%d", &n , &k );
	t = 0;  ans = abs(n-k);
	g = k , h = -1; 
	while ( g > 1 ) 
	{
		if ( h == -1 )
			if ( g&1 ) h =(g>>1)+1, g >>=1, t +=2; 
			else g >>=1, t++; 
		else {
			if ( g&1 ) g = h>>1; else g = g>>1; 
			h = -1; 
			t++;
		}
		ans = min( ans , t+abs(n-g) );
		if ( h != -1 ) ans = min( ans , t+abs(n-h) );
	}
	printf("%d\n" , ans );
}

• Re:发一个非bfs的500B版本，不解释 (741) betterfish 2013-09-17 17:00:27