uva 10120

bfs搜索  当n大于等于49 是 总是可能的 ~ http://www.algorithmist.com/index.php/UVa_10120

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <vector>
#include <sstream>
#include <string>
#include <cstring>
#include <algorithm>
#include <iostream>
#define maxn 2010
#define INF 0x7fffffff
#define inf 10000000
#define MOD 1000000007
#define ull unsigned long long
#define ll long long
using namespace std;

int m, n;
struct node
{
    int now, step;
    node(int i, int j)
    {
        now = i, step = j;
    }
};

bool solve()
{
    queue<node> q;
    q.push(node(1, 1));
    while(!q.empty())
    {
        node u = q.front();
        q.pop();
        if(u.now == m)
            return 1;
        if(u.now+2*(u.step+1)-1 <= n)
            q.push(node(u.now+2*(u.step+1)-1, u.step+1));
        if(u.now-2*(u.step+1)+1 >= 1)
            q.push(node(u.now-2*(u.step+1)+1, u.step+1));
    }
    return 0;
}

int main()
{

    while(scanf("%d%d", &n, &m) == 2 && n+m)
    {
        if(n >= 50 || solve()) puts("Let me try!");
        else puts("Don't make fun of me!");
    }
    return 0;
}