四、程序填充题
36. (1) j = i + 1
(2) >
(3) b [i] = b [j]
37. (1) digit = 0, blank = 0, other = 0
(2) c> =′0′&&c< = ′9′
(3) ++ other或者other ++
38. (1) &a[i] 或者a + i
(2) x = = a[i]
(3) <

五、程序设计题
下述答案仅供参考，若采用其它方法答案，只要正确实现题目要求即可。
39. main ()
{int i
for(i = 10；i< = 1000；i ++ )
if((i??2 = = 0)&&(i??3 = = 0)&&(i??7 = = 0))
printf(″i = ??d \ n″，i)；
}
40. main ()
{int a = 0, b = 0, i；
for(i = 2；i< = 100；i + = 2)
{ 2 + = i；b + = i - 1；}
printf(″Sum of even number = ??d \ n″，a)；
printf(″Sum of odd number = ??d \ n″，b)；
}
41. # include″string.h″
main ()
{int i, n；static char str[80]；
gets(str)；n = strlen(str)；
for(i = 0；i<n/2；i ++ )
if(str[i]! = str[n - 1 -i])
{printf(″No! \ n″)；break；}
if(i = = n/2) printf(″Yes! \ n″)；