35 lines
460 B
C++
35 lines
460 B
C++
#include<cstdio>
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#include<queue>
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using namespace std;
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int ans[133334]={0},n,k,x;
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int main()
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{
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queue<int>q;
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scanf("%d%d",&n,&k);
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q.push(n);
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ans[n]=1;
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do
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{
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x=q.front();
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if(x>0&&ans[x-1]==0)
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{
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ans[x-1]=ans[x]+1;
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q.push(x-1);
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}
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if(x<k&&ans[x+1]==0)
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{
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ans[x+1]=ans[x]+1;
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q.push(x+1);
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}
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if(x*3<=k*2&&ans[x*2]==0)
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{
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ans[x*2]=ans[x]+1;
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q.push(x*2);
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}
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q.pop();
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}
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while(ans[k]==0);
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printf("%d\n",ans[k]-1);
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return 0;
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}
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