题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1525

Euclid's Game

Problem Description Two players, Stan and Ollie, play, starting with two natural numbers. Stan, the first player, subtracts any positive multiple of the lesser of the two numbers from the greater of the two numbers, provided that the resulting number must be nonnegative. Then Ollie, the second player, does the same with the two resulting numbers, then Stan, etc., alternately, until one player is able to subtract a multiple of the lesser number from the greater to reach 0, and thereby wins. For example, the players may start with (25,7): 25 7 11 7 4 7 4 3 1 3 1 0  an Stan wins.    Input The input consists of a number of lines. Each line contains two positive integers giving the starting two numbers of the game. Stan always starts.   Output For each line of input, output one line saying either Stan wins or Ollie wins assuming that both of them play perfectly. The last line of input contains two zeroes and should not be processed.    Sample Input 34 12 15 24 0 0   Sample Output Stan wins Ollie wins  

给出两个数a、b，将大的数（a）-若干个小的数（b）的倍数，最后得到有一个数为0的话就赢了。 总会出现的一个局面就是b，a%b。 （1）a==b  a%b==0 先手获胜。  （2）b<a<b*2  （0<a-b<b）一直走下去 看谁面对满足（1）的条件。 （3）a/b>=2  先手可以选择谁面对 b，a%b这样的局势。

[cpp]  view plain  copy  print ? #include<iostream>   #include<cstring>   using namespace std;   int main()   {       int a,b;       while(cin>>a>>b)       {           if(a==0&&b==0)           break;           if(a<b)           swap(a,b);           bool flag=1;           while(b)           {               if(a%b==0||a/b>=2)               {                   break;               }               a=a-b;               swap(a,b);               flag=!flag;           }           if(flag)           cout<<"Stan wins"<<endl;           else           cout<<"Ollie wins"<<endl;       }    }