[poj2348]Euclid's Game

The SG -defined functions, can be found when y <x <2y time, SG (X, Y) = [SG (XY, Y) = 0] , i.e., there must be both a 0 , so there SG (x + ky, Y) MEX = (0, ......)> 0 .

In other words, a state for SG (X, Y) (X> Y) , if $ x \ ge 2y $ is the winning state, and when x <2y direct continuation judging SG (xy, y) of this state can be. The total time complexity requirements similar GCD , i.e. $ O (LOG_ {n-2}) $ .

 1 #include<cstdio>
 2 #include<algorithm>
 3 using namespace std;
 4 int a,b;
 5 int main(){
 6    while (scanf("%d%d",&a,&b)!=EOF){
 7       if (a<b)swap(a,b);
 8       if (!a)return 0;
 9       int ans=0;
10       while (b){
11          if ((a-b>b)||(a%b==0))break;
12          a-=b;
13          swap(a,b);
14          ans^=1;
15       }
16       if (ans)printf("Ollie wins\n");
17       else printf("Stan wins\n");
18    }
19 }

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