feat: Add conversion/decimal_to_anybase.c algorithm (#872)

* added Conversion/decimal_to_anybase.c

* Added Converstions/decimal_to_any_base.c

* Enhencement of decimal_to_any_base.c

* Update conversions/decimal_to_any_base.c

Co-authored-by: David Leal <halfpacho@gmail.com>

* Update conversions/decimal_to_any_base.c

Co-authored-by: David Leal <halfpacho@gmail.com>

* updating DIRECTORY.md

* Update conversions/decimal_to_any_base.c

Co-authored-by: David Leal <halfpacho@gmail.com>

* Update conversions/decimal_to_any_base.c

Co-authored-by: David Leal <halfpacho@gmail.com>

* text enhencement and debugging

* comments norming

* builtin int types declacration changed into arch optimized int types

* comments norming

* Adding booleans and int types normalization

* Translation of the program into a function and tests added

* Commentary rewriting in decimal_to_anybase and code beautify

* added 1 comments in main and code beautify

* Commentary norming

* Code norming

* Apply suggestions from code review

Co-authored-by: Votre Nom <Vous@exemple.com>
Co-authored-by: David Leal <halfpacho@gmail.com>
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

DIRECTORY.md

@@ -18,6 +18,7 @@
   * [Binary To Hexadecimal](https://github.com/TheAlgorithms/C/blob/master/conversions/binary_to_hexadecimal.c)
   * [Binary To Octal](https://github.com/TheAlgorithms/C/blob/master/conversions/binary_to_octal.c)
   * [C Atoi Str To Integer](https://github.com/TheAlgorithms/C/blob/master/conversions/c_atoi_str_to_integer.c)
+  * [Decimal To Any Base](https://github.com/TheAlgorithms/C/blob/master/conversions/decimal_to_any_base.c)
   * [Decimal To Binary](https://github.com/TheAlgorithms/C/blob/master/conversions/decimal_to_binary.c)
   * [Decimal To Binary Recursion](https://github.com/TheAlgorithms/C/blob/master/conversions/decimal_to_binary_recursion.c)
   * [Decimal To Hexa](https://github.com/TheAlgorithms/C/blob/master/conversions/decimal_to_hexa.c)

conversions/decimal_to_any_base.c

@@ -0,0 +1,169 @@
+/**
+ * @file
+ * @author [jucollet972](https://github.com/jucollet972)
+ * @brief [Decimal to any-base](http://codeofthedamned.com/index.php/number-base-conversion) is a C function wich convert positive decimal
+ * integer to any positive ascii base with the base's alphabet given in input and return it in a dynamically allocated string(recursive way)
+ */
+
+#include <stdio.h>   /// for IO operations
+#include <string.h>  /// for strchr and strlen
+#include <stdint.h>  /// for CPU arch's optimized int types
+#include <stdbool.h> /// for boolean types
+#include <assert.h>  /// for assert
+#include <stdlib.h>  /// for malloc and free
+
+/**
+ * @brief Checking if alphabet is valid
+ * @param base alphabet inputed by user
+ * @return int64_t as success or not
+ */
+bool isbad_alphabet(const char* alphabet) {
+	uint64_t len = strlen(alphabet);
+	
+	/* Checking th lenght */	
+	if (len < 2) {
+		return true;
+	}
+	/* Browse the alphabet */
+	for (int i = 0; i < len ; i++) {
+		/* Searching for duplicates */ 
+		if (strchr(alphabet + i + 1, alphabet[i]))
+			return true;
+	}
+	return false;
+}
+
+/**
+ * @brief Calculate the final length of the converted number
+ * @param nb to convert
+ * @param base calculated from alphabet
+ * @return Converted nb string length 
+ */
+uint64_t converted_len(uint64_t nb, short base) {
+	/* Counting the number of characters translated to the base*/
+	if (nb > base - 1) {
+		return (converted_len(nb/base, base) + 1);
+	}
+	return 1;
+}
+
+/**
+ * @brief Convert positive decimal integer into anybase recursively
+ * @param nb to convert
+ * @param alphabet inputed by user used for base convertion
+ * @param base calculated from alphabet
+ * @param converted string filled with the convertion's result
+ * @return void
+ */
+void convertion(uint64_t nb, const char* alphabet, short base, char* converted) {
+	/* Recursive convertion */
+	*(converted) = *(alphabet + nb%base);
+	if (nb > base - 1) {
+		convertion(nb/base, alphabet, base, --converted);
+	}
+}
+
+/**
+ * @brief decimal_to_anybase ensure the validity of the parameters and convert any unsigned integers into any ascii positive base
+ * @param nb to convert
+ * @param base's alphabet
+ * @returns nb converted on success
+ * @returns NULL on error
+ */
+char* decimal_to_anybase(uint64_t nb, const char* alphabet) {
+	char* converted;
+
+	/* Verify that alphabet is valid */
+	if (isbad_alphabet(alphabet)) {
+		return NULL;
+	}
+	/* Convertion */
+	uint64_t base = strlen(alphabet);
+	uint64_t final_len = converted_len(nb, base);
+	converted = malloc(sizeof(char) * (final_len + 1));
+	converted[final_len] = 0;
+	convertion(nb, alphabet, base, converted + final_len - 1);
+	return converted;
+}
+
+
+/**
+ * @brief Self-test implementations
+ * @returns void
+ */
+static void test()
+{
+	char* ret = NULL;
+	char* reference = NULL;
+
+	/* min dec*/
+	reference = "0";
+	ret = decimal_to_anybase(0, "0123456789");
+	for (int i = 0; i < strlen(reference) && i < strlen(ret); i++) {
+		assert(ret[i] == reference[i]);
+	}
+	if (ret != NULL) {
+		free(ret);
+	}
+	
+	/* max dec*/
+	reference = "18446744073709551615";
+	ret = decimal_to_anybase(18446744073709551615, "0123456789");
+	for (int i = 0; i < strlen(reference) && i < strlen(ret); i++) {
+		assert(ret[i] == reference[i]);
+	}
+	if (ret != NULL) {
+		free(ret);
+	}
+	
+	/* negative dec*/
+	reference = "18446744073709551615";
+	ret = decimal_to_anybase(-1, "0123456789");
+	for (int i = 0; i < strlen(reference) && i < strlen(ret); i++) {
+		assert(ret[i] == reference[i]);
+	}
+	if (ret != NULL) {
+		free(ret);
+	}
+
+	/* bin */
+	reference = "101010";
+	ret = decimal_to_anybase(42, "01");
+	for (int i = 0; i < strlen(reference) && i < strlen(ret); i++) {
+		assert(ret[i] == reference[i]);
+	}
+	if (ret != NULL) {
+		free(ret);
+	}
+	
+	/* octal */
+	reference = "52";
+	ret = decimal_to_anybase(42, "01234567");
+	for (int i = 0; i < strlen(reference) && i < strlen(ret); i++) {
+		assert(ret[i] == reference[i]);
+	}
+	if (ret != NULL) {
+		free(ret);
+	}
+	
+	/* hexa */
+	reference = "2A";
+	ret = decimal_to_anybase(42, "0123456789ABCDEF");
+	for (int i = 0; i < strlen(reference) && i < strlen(ret); i++) {
+		assert(ret[i] == reference[i]);
+	}
+	if (ret != NULL) {
+		free(ret);
+	}
+	printf("[+] All tests have successfully passed!\n");
+}
+
+/**
+ * @brief Main function
+ * @returns 0 on exit 
+ */
+int main()
+{
+	test(); // run self-test implementations
+	return 0;
+}