Initial commit

assignment/pyramid_of_numbers.c

@@ -0,0 +1,80 @@
+/*----------------------------------------------------------
+ *				HTBLA-Leonding / Class: <your class>
+ * ---------------------------------------------------------
+ * Exercise Number: 0
+ * Title:			Pyramid of Numbers
+ * Author:			<your name>
+ * ----------------------------------------------------------
+ * Description:
+ * Calculates a pyramid of numbers, i.e., it multiplies a big
+ * integer by the number 2, its result by 3, etc. and then
+ * returns to the original value by subsequently dividing,
+ * again starting by 2, 3, etc.
+ * ----------------------------------------------------------
+ */
+#include <stdio.h>
+
+/// The maximum number of digits allowed in a big int.
+#define MAX_DIGITS 80
+
+/** BigInt represents an integer number which can have MAX_DIGITS digits
+*** @see MAX_DIGITS
+*/
+struct BigInt {
+	/** number of digits of the big int. */
+	int digits_count;
+
+	/** array of digits of big int. */
+	unsigned int the_int[MAX_DIGITS];
+};
+
+/** strtobig_int converts a string into a BigInt. If strtobig_int runs
+*** against a character not between '0' and '9' the conversion stops
+*** at this point.
+*** @param *str The string to be converted.
+*** @param len Number of characters in string to be converted.
+*** @param *big_int The converted string now as BigInt.
+* @return The number of characters converted.
+*/
+int strtobig_int(const char* str, int len, struct BigInt* big_int);
+
+/** print_big_int() prints a BigInt.
+*** @param *big_int The BigInt to be printed.
+*/
+void print_big_int(const struct BigInt *big_int);
+
+/** multiply() multiplies a BigInt by an int.
+*** @param big_int The BigInt to be multiplied.
+*** @param factor The int value which is multiplied by BigInt.
+*** @param *big_result The result of the multiplication.
+*/
+void multiply(const struct BigInt* big_int, int factor, struct BigInt* big_result);
+
+/** divide() multiplies a BigInt by an int.
+*** @param big_int The BigInt to be divided.
+*** @param divisor The int value by which we want to devide big_int.
+*** @param *big_result The result of the division.
+*/
+void divide(const struct BigInt* big_int, int divisor, struct BigInt* big_result);
+
+/** copy_big_int() copies a BigInt to another BigInt.
+*** @param from The source where we want to copy from.
+*** @param *to The target where we want to copy to.
+*/
+void copy_big_int(const struct BigInt* from, struct BigInt* to);
+
+/**
+*** main() reads the base number from which the pyramid has to be calculated
+*** into an array of char. The max. length of this number is MAX_DIGITS.
+*** The number is checked to contain only digits. If not the program exits.
+*** Then the inputted number is converted into a big int by calling the
+*** function strtobig_int().
+*** After the conversion the tower is calculated by calling the functions
+*** multiply(), print_big_int(), and copy_big_int() consecutively from 2 to
+*** 9 and then again with divide() instead of multiply() from 2 to 9.
+***
+*/
+int main(int argc, char* argv[])
+{
+	return 0;
+}