TCPL学习笔记：4-12以及4-13。关于使用递归的问题。

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 void Itoa(int num, char * s);
 4 int main(void)
 5 {
 6     char s[20];
 7     Itoa(1234567, s);
 8     printf("The str now is %s", s);
 9     return 0;
10 }
11 
12 void Itoa(int n, char * s)
13 {
14     static int i = 0;
15     if(n < 0)
16     {
17         s[i++] = ‘-‘;
18         s[i] = ‘\0‘;
19         n = -n;
20     }
21     else
22     {
23         if(n/10)
24             Itoa(n/10, s);
25         s[i++] = ‘0‘ + n%10;
26         s[i] = ‘\0‘;
27     }
28 
29 }

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 void reversed(char * s, char * d);
 4 int main(void)
 5 {
 6     char s1[20] = "wangcheng";
 7     char s2[20];
 8     reversed(s1, s2);
 9     printf("The reversed string is : %s", s2);
10     return 0;
11 }
12 
13 void reversed(char * s, char * d)
14 {
15     static int i = 0;
16     static int j = 0;
17     if(s[i+1] != ‘\0‘)
18     {
19         i++;
20         reversed(s, d);
21     }
22          d[j++] = s[i--];
23          d[j] = ‘\0‘;
24 }

1 编译运行结果为：The reversed string is : gnehcgnaw
2 Process returned 0 (0x0)   execution time : 0.009 s
3 Press any key to continue.