// ==========================================================================
// Print Bits
// ==========================================================================
// Print a range of bits from a given input word. 

// Inf2C-CS Coursework 1. Task A 
// PROVIDED file, to be used as model for writing MIPS code.

// Paul Jackson
//  8 Oct 2013

//---------------------------------------------------------------------------
// C definitions for SPIM system calls
//---------------------------------------------------------------------------
#include <stdio.h>

int read_char() { return getchar(); }
void read_string(char* s, int size) { fgets(s, size, stdin); }

void print_char(int c)     { putchar(c); }   
void print_string(char* s) { printf("%s", s); }


//---------------------------------------------------------------------------
// PRINT_BITS function
//---------------------------------------------------------------------------

// Print bits n-1 ... 0 of input word w, using a '#' character for each 1 bit,
// and a '.' character for each 0 bit. 

// Assume n > 0

void print_bits(unsigned int w, int n) {
    unsigned int mask = 0x1 << (n - 1);
    while (mask != 0) {
        unsigned int v = w & mask;
        if (v != 0) {
            print_char('#');
        }
        else {
            print_char('.');
        }
        mask = mask >> 1;
    }
    return;
}

//---------------------------------------------------------------------------
// MAIN function
//---------------------------------------------------------------------------
// A couple of test cases

int main (void)
{
  print_bits(0xfff,10);
  print_char('\n');
  print_bits(0xa5,12);
  print_char('\n');
  return 0;
}


//---------------------------------------------------------------------------
// End of file
//---------------------------------------------------------------------------