add : solution of the is_palindrome

Author: crumbs22

valid-palindrome/aa601.c

@@ -0,0 +1,27 @@
+bool isPalindrome(char* s) {
+	int		i;
+	int		j;
+	int		size;
+	char	tmp;
+	int		flag;
+
+	i = 0;
+	size = strlen(s);
+	j = size - 1;
+	flag = 1;
+	while (i < j) {
+		if (!isalnum(s[i])) {
+			++i;
+			continue ;
+		}
+		else if (!isalnum(s[j])) {
+			--j;
+			continue ;
+		}
+		if (tolower(s[i++]) != tolower(s[j--])) {
+			flag = 0;
+			break ;
+		}
+	}
+	return (flag);
+}