View Code of Problem 2911

#include<iostream>
#include<cstring>
#include<queue>
using namespace std;
int n,k;
int f[3]={-1,1,0};
int v[100005];
struct node{
	int p;
	int s;
};
int bfs(){
	node x;
	x.p=n;
	x.s=0;
	v[n]=1;
	queue<node>q;
	q.push(x);
	while(!q.empty()){
		for(int i=0;i<3;++i){
			int xx;
			if(i!=2)
			xx=q.front().p+f[i];
			else
			xx=q.front().p*2;
			if(xx>=0&&xx<100004&&v[xx]==0){
				node sp;
				sp.s=q.front().s+1;
				sp.p=xx;
				v[xx]=1;
				if(xx==k)
				return sp.s;
				else
					q.push(sp);
			}
		}
		q.pop();
	}
	return 0;
	
}
int main(){
	while(cin>>n>>k){
		memset(v,0,sizeof(v));
		cout<<bfs()<<endl;
	}
}