itoa function : doesn't work for -ve number ?????
Hi !
This is a function itoa(int n , char s[]) which converts an integer to a string. I have tried to implement it recursively. The program works fine except one problem:
IT DOESN"T WORK FOR -ve NUMBERS ??? WHY ????????
I DON"T UNDERSTAND ???? CAN ANY ONE HELP ME ON THIS !!!
The code is as follows :
Code:
#include<stdio.h>
#include<string.h>
/* *********************************************************************************** */
/* This program defines a recursive function itoa() which converts integer to a string
/* *********************************************************************************** */
static int i = 0; /* variables to keep track of the index of the string */
static int sign = 1; /* variable to keep track of the sign of the integer */
void reverse(char s[]); /* function declaration : function to reverse a string */
void itoa(int n, char s[])
{
if(i == 0) /* make the number positive if it is negative */
if (sign < 0)
{
n = -n;
sign *= -1;
}
/* store each digit in the string ( in reverse order )*/
if(n)
{
s[i++] = n%10 + '0';
itoa(n/10, s);
}
else
{
if (sign < 0) /* if the number was negative place a -ve sign at the end */
{
s[i++] = '-';
s[i] = '\0';
reverse(s);
return; /* place a NULL character to mark the end of the string */
}
else
{
s[i] = '\0';
reverse(s);
return;
}
}
}
void reverse(char s[])
{
int i, j, temp; /* local variable to reverse the string */
for( i = 0, j = (strlen(s) - 1); i < j; i++, j--)
{
temp = s[i];
s[i] = s[j];
s[j] = temp;
}
}
int main()
{
char s[]= "";
int n = -10;
itoa(n, s);
printf("%s\n", s);
return 0;
}
