sol1.c File Reference

Problem 25 solution implemented using arbitrarily large numbers represented as arrays More...

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

Include dependency graph for sol1.c:

Macros
#define	MAX_DIGITS   1000
	maximum number of digits

Functions
unsigned int	add_numbers (unsigned char *a, unsigned char *b, unsigned char *c, int N)
	Function to add arbitraty length decimal integers stored in an array. More...
int	print_number (unsigned char *number, int N)
	Print a large number.
unsigned int	get_digits (unsigned char *number)
	Get number of digits in a large number.
int	main (int argc, char *argv[])
	Main function.

Detailed Description

Problem 25 solution implemented using arbitrarily large numbers represented as arrays

Author

Krishna Vedala

Function Documentation

add_numbers()

unsigned int add_numbers	(	unsigned char *	a,
		unsigned char *	b,
		unsigned char *	c,
		int	N
	)

Function to add arbitraty length decimal integers stored in an array.

a + b = c = new b

{
    unsigned char carry = 0;
    unsigned int i;
 
    for (i = 0; i < N; i++)
    {
        // printf("\t%d + %d + %d ", a[i], b[i], carry);
        c[i] = carry + a[i] + b[i];
        if (c[i] > 9) /* check for carry */
        {
            carry = 1;
            c[i] -= 10;
        }
        else
        {
            carry = 0;
        }
        // printf("= %d, %d\n", carry, c[i]);
    }
 
    while (carry != 0)
    {
        // printf("\t\t...adding new digit\n");
        // printf("\t0 + %d + %d ", b[i], carry);
        c[i] = carry + c[i];
        if (c[i] > 9)
        {
            carry = 1;
            c[i] -= 10;
        }
        else
        {
            carry = 0;
        }
        // printf("= %d, %d\n", carry, c[i]);
        i++;
    }
    return i;
}