1 files changed, 58 insertions, 0 deletions
diff --git a/libft/src/mem/ft_memmem.c b/libft/src/mem/ft_memmem.c
new file mode 100644
index 0000000..fa1446c
--- /dev/null
+++ b/libft/src/mem/ft_memmem.c
@@ -0,0 +1,58 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   ft_memmem.c                                        :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: cacharle <marvin@42.fr>                    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2020/02/13 01:54:55 by cacharle          #+#    #+#             */
+/*   Updated: 2020/02/13 21:04:46 by cacharle         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft_mem.h"
+
+#define BAD_TABLE_SIZE 256
+
+static void	st_bad_table_init(size_t bad_table[BAD_TABLE_SIZE],
+									const char *little, size_t little_len)
+{
+	size_t	i;
+
+	i = 0;
+	while (i < BAD_TABLE_SIZE)
+		bad_table[i++] = little_len;
+	i = 0;
+	while (i < little_len - 1)
+	{
+		bad_table[(int)little[i]] = little_len - i - 1;
+		i++;
+	}
+}
+
+static int	st_memcmp_end(const void *s1, const void *s2, size_t n)
+{
+	while (n-- > 0)
+		if (*(t_ftbyte*)(s1 + n) != *(t_ftbyte*)(s2 + n))
+			return (*(t_ftbyte*)(s1 + n) - *(t_ftbyte*)(s2 + n));
+	return (0);
+}
+
+void		*ft_memmem(const void *big, size_t big_len,
+							const void *little, size_t little_len)
+{
+	size_t	i;
+	size_t	bad_table[BAD_TABLE_SIZE];
+
+	if (big_len < little_len || little_len == 0 || big_len == 0)
+		return (NULL);
+	st_bad_table_init(bad_table, little, little_len);
+	i = 0;
+	while (i <= big_len - little_len)
+	{
+		if (st_memcmp_end(big + i, little, little_len) == 0)
+			return ((void*)big + i);
+		i += bad_table[*(t_ftbyte*)(big + i + little_len - 1)];
+	}
+	return (NULL);
+}