CS256 - Principles of Structured Design Fall 2021

Displaying ./code/cs256su21code/jul15/binary.c

/*

A function that prints out the number in binary


*/

#include <stdio.h>
#include <stdlib.h>

void printBinaryNum(int num, int numBits);

int main(int argc, char *argv[]){

	if(argc < 3){
		printf("Usage: %s <number> <number of bits to print>\n", argv[0]);
		exit(1);
	}

	int n, bits;

	n = atoi(argv[1]);
	bits = atoi(argv[2]);

	printBinaryNum(n, bits);

	return 0;
}

// 45 0010 1101

//this functiontakes in 2 arguments, the number we;re printing, and the number of bits we're printing
void printBinaryNum(int num, int numBits){

	int bit;

	//we start at the leftmost bit, then count down to bit 0.
	//since we start counting our bits with the rightmost bit 
	//being bit 0, the leftmost bit will be bit (numBits-1).
	for(int i = numBits -1; i >= 0; i--){
		bit = (num >> i) & 1; //the number is right shifted "i" times, and then AND'ed with 1
		if(bit == 1)
			putchar('1');
		else
			putchar('0');
	}

	printf("\n");

}