OJ-Problems-Source/HDOJ/2717_autoAC.cpp

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