UtilLib

ft_itoa.c

@@ -0,0 +1,104 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_itoa.c                                          :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: hexplor <marvin@42.fr>                     +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2023/11/22 15:16:11 by hexplor           #+#    #+#             */
+/*   Updated: 2023/11/30 07:44:52 by yantoine         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+
+static int	ft_n_digit(int n)
+{
+	long	index;
+
+	if (n == 0)
+		return (1);
+	index = 0;
+	while (n != 0)
+	{
+		n /= 10;
+		index++;
+	}
+	return (index);
+}
+
+static int	ft_pow(int n)
+{
+	long	index;
+
+	index = 1;
+	while (n != 0)
+	{
+		index *= 10;
+		n--;
+	}
+	return (index / 10);
+}
+
+static void	ft_set_number(char *tab)
+{
+	long	index;
+
+	index = 0;
+	while (index != 11)
+	{
+		tab[index] = index + '0';
+		index++;
+	}
+	tab[index] = '\0';
+}
+
+static void	ft_set_digit(long nbr_digit, long index, char *nbr, long n)
+{
+	char	digit[15];
+	long	pow;
+
+	if (n == 0)
+	{
+		*nbr = '0';
+		*(nbr + 1) = 0;
+		return ;
+	}
+	ft_set_number(digit);
+	pow = ft_pow(nbr_digit);
+	while (nbr_digit != 0)
+	{
+		*(nbr + index++) = digit[(n / pow) % 10];
+		nbr_digit--;
+		pow /= 10;
+	}
+	*(nbr + index++) = '\0';
+}
+
+char	*ft_itoa(int n)
+{
+	char	*nbr;
+	long	index;
+	long	n2;
+	long	nbr_digit;
+
+	n2 = (long) n;
+	nbr_digit = ft_n_digit(n);
+	index = 0;
+	if (n2 < 0)
+	{
+		nbr = ft_calloc((nbr_digit + 2), 1);
+		if (!nbr)
+			return (NULL);
+		*(nbr + index++) = '-';
+		n2 *= -1;
+	}
+	else
+	{
+		nbr = ft_calloc((nbr_digit + 1), 1);
+		if (!nbr)
+			return (NULL);
+	}
+	ft_set_digit(nbr_digit, index, nbr, n2);
+	return (nbr);
+}