C语言，用递归法并通过函数调用方法将一个整数换成字符串，如整数123对应的字符串为“123”

void append(char *s, char c) { int i; for(i = 0; s[i]; i++); s[i++] = c; s[i] = '\0'; } void _trans(int a, char *s) { int tmp; if(a == 0) return; tmp = a%10; tmp += 48; _trans(a/10, s); append(s, (char)tmp); }