/***********************************************************
 * bitcount.c
 * Unit 7 lecture notes
 * Counts how many bits are set in a value
 **********************************************************/
#include <stdio.h>
#include "inputlib.h"

unsigned char setBit(unsigned char val, int pos);
unsigned char unsetBit(unsigned char val, int pos);

int main(void)
{
  unsigned char val = 0xee; // test value 11101110
  int i, count = 0, numBits = sizeof(val) * 8;

  // loop through each bit and determine if it's a 1 or 0.
  // If it's 1, increment count.
  for (i = 0; i < numBits; i++) {
    if ((val & (1 << i)) != 0) {
      printf("Bit %d set!\n", i);
      count++;
    } else {
      printf("Bit %d is not set!\n", i);
    }
  }
  printf("There are %d bits set in %#x.\n", count, val);

  int bitToSet, bitToUnset;

  printf("This is the current bitset: %#x.\n", val);
  printf("Enter a bit you want to set: ");
  bitToSet = getInt();

  val = setBit(val, bitToSet);
  printf("This is the current bitset: %#x.\n", val);

  printf("Enter a bit you want to unset: ");
  bitToUnset = getInt();
  val = unsetBit(val, bitToUnset);
  printf("This is the current bitset: %#x.\n", val);

  return 0;
}


unsigned char setBit(unsigned char val, int pos)
{
  if (pos >= sizeof(unsigned char) * 8 || pos < 0) {
    printf("Bit position is out of bounds.\n");
  }
  return val | (1 << pos);
}

unsigned char unsetBit(unsigned char val, int pos)
{
  if (pos >= sizeof(unsigned char) * 8 || pos < 0) {
    printf("Bit position is out of bounds.\n");
  }
  return val & ~(1 << pos);
}