ch4_prog_proj_05.c

/*********************************************************
 * From C PROGRAMMING: A MODERN APPROACH, Second Edition *
 * By K. N. King                                         *
 * Copyright (c) 2008, 1996 W. W. Norton & Company, Inc. *
 * All rights reserved.                                  *
 * This program may be freely distributed for class use, *
 * provided that this copyright notice is retained.      *
 *********************************************************/

// (Section 4.1, Pages 57-58)

/*
 * ch4_prog_proj_05.c
 *
 *  Created on: Apr 1, 2024
 *      Author: Mahmoud Hamdy
 */

// Programming Project 5: Computing a UPC check digit (Rewritten)

#include <stdio.h>

int main(void)
{
	int d, i1, i2, i3, i4, i5, j1, j2, j3, j4, j5,
	first_sum, second_sum, total;

	printf("Enter the first 11 digits of a UPC: ");
	scanf("%1d%1d%1d%1d%1d%1d%1d%1d%1d%1d%1d",
			&d, &i1, &i2, &i3, &i4, &i5, &j1, &j2, &j3, &j4, &j5);

	first_sum = d + i2 + i4 + j1 + j3 + j5;
	second_sum = i1 + i3 + i5 + j2 + j4;
	total = 3 * first_sum + second_sum;

	printf("Check digit: %d\n", 9 - ((total - 1) % 10));

	return 0;
}