59 lines
1.1 KiB
C++
59 lines
1.1 KiB
C++
#include <stdio.h>
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#include <cstring>
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#include <cmath>
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#include <cstdlib>
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#include <iostream>
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#include <algorithm>
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#include <queue>
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#include <stack>
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#include <map>
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#include <vector>
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using namespace std;
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int n,m;
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int vis[200005];
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struct node
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{
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int x;
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int step;
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};
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int bfs(int n,int m)
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{
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int i;
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queue<node>q;
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node st,ed;
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st.x=n;
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st.step=0;
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vis[st.x]=1;
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q.push(st);
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while(!q.empty())
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{
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st=q.front();
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q.pop();
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if(st.x==m)
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return st.step;
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for(i=0;i<3;i++)
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{
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if(i==0)
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ed.x=st.x+1;
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if(i==1)
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ed.x=st.x-1;
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if(i==2)
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ed.x=st.x*2;
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if(vis[ed.x] || ed.x<0 ||ed.x>100000)
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continue;
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vis[ed.x]=1;
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ed.step=st.step+1;
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q.push(ed);
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}
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}
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}
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int main()
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{
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while(cin>>n>>m)
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{
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memset(vis,0,sizeof(vis));
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int ans=bfs(n,m);
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cout<<ans<<endl;
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}
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}
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