习题5-2 使用函数求奇数和

 1 int even( int n )
 2 {
 3     int ret = 1;
 4     
 5     if (n < 0)
 6     {
 7         n = -n;
 8     }
 9     if (n % 2 == 1)
10     {
11         ret = 0;
12     }
13     
14     return ret;
15 } 
16 int OddSum( int List[], int N )
17 {
18     int sum = 0;
19     for (int i = 0; i < N; i++)
20     {
21         if (even(List[i]) == 0)
22         {
23             sum = sum + List[i];
24         }
25     }
26     
27     return sum;
28 }