【杭电】[2717]Catch That Cow

#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;
int n,e;
int MAX=100200;
int dis[100200];
void bfs(int m) {
queue<int>q;
q.push(m);
while(q.front()!=e) {
int t=q.front();
if(t+1<MAX&&!dis[t+1]) {
dis[t+1]=dis[t]+1;
q.push(t+1);
}
if(t-1>=0&&!dis[t-1]) {
dis[t-1]=dis[t]+1;
q.push(t-1);
}
if(t*2<MAX&&!dis[t*2]) {
dis[t*2]=dis[t]+1;
q.push(t*2);
}
if(dis[e])
break;
q.pop();
}
return ;
}
int main() {
while(scanf("%d %d",&n,&e)!=EOF) {
memset(dis,0,sizeof(dis));
bfs(n);
printf("%d\n",dis[e]);
}
return 0;
}