1100. 抓住那头牛最短路的特殊移动

Posted 2021-11-06 幽殇默

https://www.acwing.com/problem/content/1102/

#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;
int startx,endx;
int d[N],st[N];
int bfs()
{
    queue<int>q; q.push(startx);
    st[startx]=1;
    while(q.size())
    {
        int u=q.front(); q.pop();
        if(u==endx) return d[u];
        if(u-1>=0&&!st[u-1]) q.push(u-1),st[u-1]=1,d[u-1]=d[u]+1;
        if(u+1<N&&!st[u+1]) q.push(u+1),st[u+1]=1,d[u+1]=d[u]+1;
        if(u*2<N&&!st[u*2]) q.push(u*2),st[u*2]=1,d[u*2]=d[u]+1;
    }
}
int main(void)
{
    cin>>startx>>endx;
    cout<<bfs()<<endl;
    return 0;
}