POJ.2975 Nim

1.Problem
http://poj.org/problem?id=2975

2.Idea
Calculate Nim.

3.Source

 int n;  
 int a[1100];  
 void solve()  
 {  
      while (scanf("%d", &n)) {  
           if (n == 0) break;  
           int x = 0;  
           REP(i, n) {  
                scanf("%d", &a[i]);  
                x ^= a[i];  
           }  
           int ans = 0;  
           if (x > 0) {  
                REP(i, n) {  
                     int tmp = x ^ a[i];  
                     if (tmp <= a[i]) ans++;  
                }  
           }  
           printf("%d\n", ans);  
      }  
 }