poj 2348

Euclid's Game

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 7418		Accepted: 3022

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

Source

Waterloo local 2002.09.28

 

分两种情况 b - a < a b - a > a

第一种情况别无选择，第二种情况必胜，由此可得答案

 

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

int a, b;

bool check() {
        bool flag = 1;
        for(;;) {
                if(a > b) swap(a,b);
                if(b % a == 0) break;
                if(b - a > a) break;
                b -= a;
                flag = !flag;
        }

        return flag;
}
int main()
{
    while(~scanf("%d%d",&a, &b) && (a + b)) {
            if(check()) {
                    printf("Stan wins
");
            } else {
                    printf("Ollie wins
");
            }
    }
    //cout << "Hello world!" << endl;
    return 0;
}