poj3278

#include<cstdio>
#include<queue>
#include<iostream>
#include<string.h>
#include<algorithm>
using namespace std;
typedef long long LL;
#define INF 9999999
const double pi=3.1415926535897932;

typedef long long LL;

//x-1,x+1,2*x

int n,k;

int q[100010];
bool vis[100010];
int st[100010];
int head,tail;

int bfs(int n)
{
memset(vis,0,sizeof(vis));
memset(st,0,sizeof(st));
head=0;tail=1;
q[head]=n;
vis
=1;
while(head<tail)
{
int x;
int u=q[head];
if(u==k)
{
return st[u];
}
head++;
for(int i=0;i<3;i++)
{
if(i==0)
x=u+1;
if(i==1)
x=u-1;
if(i==2)
x=u*2;
if(vis[x]||x>100000||x<0)
continue;
vis[x]=1;
q[tail++]=x;
st[x]=st[u]+1;
}
}
return -1;
}

int main()
{
while(~scanf("%d%d",&n,&k))
{
int ans;
ans=bfs(n);
if(ans!=-1)
cout<<ans<<endl;
}
return 0;
}