HDU-2717-Catch That Cow

HDU-2717-Catch That Cow

http://acm.hdu.edu.cn/showproblem.php?pid=2717

基本的BFS，朝3个方向搜索即可

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<queue>
using namespace std;
int n,k;
char visit[100005];
struct node
{
	int x;
	int time;
};
int go(int x)
{
	if(0<=x&&x<=100000)
	return 1;
	return 0;
}
void bfs(int n,int k)
{
	queue<node>q;
    node st,ed;
	memset(visit,0,sizeof(visit));
	visit[n]=1;
	st.x=n;
	st.time=0;
	q.push(st);
	while(!q.empty())
	{
		st=q.front();
		q.pop();
		if(st.x==k)
		{
			printf("%d\n",st.time);
			return;
		}
        if(go(2*st.x)&&!visit[2*st.x])  
		{
			ed.x=2*st.x;
			ed.time=st.time+1;
			visit[ed.x]=1;
			q.push(ed);
		}
		if(go(st.x-1)&&!visit[st.x-1])
		{
			ed.x=st.x-1;
			ed.time=st.time+1;
			visit[ed.x]=1;
			q.push(ed);
		}
		if(go(st.x+1)&&!visit[st.x+1])
		{
			ed.x=st.x+1;
			ed.time=st.time+1;
			visit[ed.x]=1;
			q.push(ed);
		}
	}
    return;
}
int main()
{
	while(scanf("%d %d",&n,&k)!=EOF)
	{
		if(n==k)
	    printf("0\n");
	    else
	    bfs(n,k);
	}
	return 0;
}