157 lines
3.3 KiB
C
157 lines
3.3 KiB
C
#include <stdio.h>
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/**
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* calculate the sum of two numbers
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* @param number1 first summand
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* @param number2 second summand
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* @return sum of the two summands
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*/
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int add(int number1, int number2);
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/**
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* calculate the product of two numbers
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* @param number1 first factor
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* @param number2 second factor
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* @return product of the two factors
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*/
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float multiply(int number1, float number2);
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/**
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* calculate the power of two integers
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* @param number1 basis
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* @param number2 exponent
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* @returns number1 to the power of number2
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*/
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int power(int number1, int number2);
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/**
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* calculate the remainder of the division of two numbers
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* @param number1 divident
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* @param number2 divisor
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* @returns number1 modulo number2
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*/
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int modulo(int number1, int number2);
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/**
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* calculate the factorial
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* @param number number to calculate factorial of
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* @return number!
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*/
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int factorial(int number);
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/**
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* calculate a fibonacci number
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* @param number what fibonacci number should be computed?
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* @returns numberth fibonacci number
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*/
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int fib(int number);
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int main(void) {
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int number1;
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int number2;
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char operator;
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printf("give me two numbers and an operator seperated by spaces\n");
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int n_matched = scanf("%d %c %d", &number1, &operator, &number2);
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if (n_matched != 3) {
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printf("Failure!\n");
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return 1;
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}
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switch (operator) {
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case '+':
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case 'a':
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case 'A':
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printf("%d\n", add(number1, number2));
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break;
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case '-':
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case 's':
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case 'S':
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printf("%d\n", add(number1, -number2));
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break;
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case '*':
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case 'm':
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case 'M':
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printf("%d\n", multiply(number1, number2));
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break;
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case '/':
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case 'd':
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case 'D':
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printf("%f\n", multiply(number1, 1.0 / number2));
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break;
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case '%':
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case 'r':
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case 'R':
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printf("%d\n", modulo(number1, number2));
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break;
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default:
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printf("are you stupid? thats not an operator!!!1\n");
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break;
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}
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return 0;
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}
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int add(int number1, int number2) {
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return number1 + number2;
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}
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float multiply(int number1, float number2) {
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/* recursive approach */
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if (number1 == 0) {
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return 0;
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}
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return number2 + multiply(number1-1, number2);
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/* looping approach */
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float multiple = 0;
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for (int i = 0; i < number1; ++i) {
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multiple += number2;
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}
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return multiple;
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/* trivial approach */
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return number1 * number2;
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}
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int power(int number1, int number2) {
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/* looping approach */
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int power_value = 1;
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for (int i = 0; i < number2; ++i) {
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power_value *= number1;
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}
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return power_value;
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/* recursive approach */
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if (number2 == 0) {
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return 1;
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}
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return multiply(number1,power(number1, number2 - 1));
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}
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int modulo(int number1, int number2) {
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return number1 % number2;
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}
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int factorial(unsigned number) {
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if (number == 0) {
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return 1;
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}
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return number * factorial(number - 1);
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}
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int fib(unsigned number) {
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if (number == 0) {
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return 0;
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}
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if (number == 1) {
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return 0;
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}
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if (number == 2) {
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return 1;
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}
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return fib(number - 1) + fib(number - 2);
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}
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