int getlen(char *s){
int n;
for(n = 0; *s != ‘\0′; s++)
n++;
return n;
}
void reverse(char s[])
{
int c,i,j;
for(i = 0,j = getlen(s) – 1; i < j; i++,j--){
c = s[i];
s[i] = s[j];
s[j] = c;
}
}
void itoa(int n,char s[])
{
int i,sign;
if((sign = n) < 0)
n = -n;
i = 0;
do{/*以反序生成数字*/
s[i++] = n%10 + '0';/*get next number*/
}while((n /= 10) > 0);/*delete the number*/
if(sign < 0)
s[i++] = ‘-’;
s[i] = ‘\0′;
reverse(s);
}