HDU 2509 博弈

#include <stdio.h>  int main()  {      int i,N,a[101];      int sum1;    int sum2;     int gx;      while(scanf("%d",&N)!=EOF)      {        sum1=0;          sum2=0;          gx=0;            for (i=0;i<N;i++)          {             scanf("%d",&a[i]);             if(a[i]>=2) sum1++;             else sum2++;              gx^=a[i];          }          if((gx!=0 && sum1!=0) || (gx==0) && sum1==0)             printf("Yes\n");          if((gx==0 && sum1>=2) || (gx!=0 && sum2%2!=0 && sum1==0)) printf("No\n");         }                                                          return 0;                   }