SG函数和SG定理

Fibonacci again and again

利用SG函数求出每一堆的SG值，如果三个值的异或和为零 先手必败态，否则，先手必胜态。

 #include <bits/stdc++.h>
 #define scanf_d(a) scanf("%d",&a)
 #define scanf_dd(a,b) scanf("%d%d",&a,&b)
 #define maxn 1000+10
 #define N 20
 //#define DEBUG
 using namespace std;
 int s[maxn],sg[maxn],fib[N];

 void getsg( int n) {
     memset(sg,,sizeof(sg));
     for ( int i = ;i <= n; i++) {
         memset(s,,sizeof(s));
         for ( int  j = ; fib[j] <= i && j <= N; j++) s[sg[i-fib[j]]]=;
         for ( int j = ; ; j++) { if(!s[j]) { sg[i] = j; break; } }
     }
 }

 int main()
 {
 #ifdef DEBUG
     freopen("Text.txt","r",stdin);
 #endif // DEBUG
     int n,m,k;
     fib[] = fib[] = ;
     for( int i = ; i <= ; i++)   fib[i] = fib[i-] + fib[i-];
     getsg();
     while(~scanf("%d%d%d",&n,&m,&k),m||n||k) {
         if(sg[n]^sg[m]^sg[k]) puts("Fibo");
         else puts("Nacci");
     }
     return ;
 }