num1.c

/* -
 * TP No. 1
 * "Doing Melissa's programming homework out of boredom"
 * (c) 2010-2011
 * Alexandre Gauthier <[email protected]>
 *
 * Specifications:
 *
 *   Read 10 numbers from the user and store them in an array
 *   of 10 elements.
 *
 *   Output the following lists:
 *    - Numbers that are less than 15
 *    - Odd Numbers
 *    - Reversed array (LIFO - Last in, first out)
 *
 *   Emphasis on the following material:
 *    - Program functionality
 *    - Functions and Arrays
 *    - Overall presentation (comments, indent, output...)
 *
 */

#include <stdio.h>

/* Poor Man's Boolean using preprocessor macros
 *  WARNING: Never test directly against TRUE! Non-zero values
 *           other than 1 would cause that test to fail!
 */
#define TRUE 1
#define FALSE 0

/* Magic Constants */
#define NUMCOUNT 10      /* Amount of numbers */ 
#define LESSTHANVAL 15   /* Value to test < against */

/* Type for pointer to test function */
typedef unsigned char (*p_testf)(int);

/* Function Prototypes */
void get_numbers(int dst[], int dstsize);
void print_array(int nums[], int size);
void print_reversed_array(int nums[], int size);
void run_test(int nums[], int size, p_testf tfunc);

unsigned char prompt_yn(const char *question);

unsigned char test_is_lt_spec(int num);
unsigned char test_is_odd(int num);


/* Program entry point */
int main (int argc, char const* argv[])
{
	int numbers[NUMCOUNT]; /* User entered numbers */
	int num_size = sizeof(numbers) / sizeof(int); /* numbers array size */
	
	/* Populate an array with pointers to the test functions */
	p_testf tests[] = { &test_is_lt_spec, &test_is_odd };
	
	int test_count = sizeof(tests) / sizeof(p_testf); /* Amount of tests */

	/* Print headers */
	printf("TP N.1, CPL - Melissa Fiorentino\n");
	printf("(c) Alexandre Gauthier 2010-2011\n");
	printf("================================\n");
	
	do {
		printf("\n");
		/* Populate numbers array with user imput */
		printf("Please enter a series of %i integers:\n", NUMCOUNT);
		get_numbers(numbers, num_size);
		printf("Thank you.\n\n");
		
		printf("Entered integers: ");
		print_array(numbers, num_size);
		printf("\n\n");
		
		/* Run tests defined in our tests array */
		printf("Running tests...\n\n");

		int i;
		for (i=0; i < test_count; i++){
			printf("Test case %i: ", i);
			run_test(numbers, num_size, tests[i]);
			printf("\nDone.\n");
		}

		printf("Integers, in reverse order of entry:\n");
		print_reversed_array(numbers, num_size);
		printf("\n");
		
	} while (prompt_yn("Run again?") == TRUE);
		
	printf("\n---- Done.\n");
	
	return 0;
}


/* get numbers from user and store them in
 * specified integer array. Array size
 * dictates the amount of numbers prompted for.
 * It will validate if the input is a decimal
 * integer before adding it to the destination array.
 *
 * dst[]    - array to store the elements into.
 * dstsize  - lenght of the integer array (in elements)
 */
void get_numbers(int dst[], int dstsize){
	int i;
	int input;
	char buffer[5];

	for(i=0; i < dstsize; i++){
		while(1){
			printf("[%i]> ", i + 1);
			fgets(buffer, sizeof(input), stdin);
			printf("\n");
			if(sscanf(buffer, "%i", &input)){
				dst[i] = input;
				break;
			} else {
				printf("Input must be a decimal integer!\n");
			}
		}
	}
}

/**
 * Print the contents of an array of integers
 * separated by spaces, on a single line.
 *
 * nums[] -- array to print
 * size   -- size of array
 */
void print_array(int nums[], int size){
	int i;
	for(i=0; i < size; i++){
		printf("%i ", nums[i]);
	}
}

/**
 * Print the contents of an array of integers 
 * in reverse order (last in, first out),
 * separated by spaces on a single line.
 * 
 * nums[] -- array to print in reverse
 * size   -- size of array
 */
void print_reversed_array(int nums[], int size){
	int i;
	for(i=size; i > 0; --i){
		printf("%i ", nums[i]);
	}
}

/**
 * Run a test on an array of integers, printing
 * only the elements that succeed the test on a
 * single line.
 *
 * nums[]  -- array of integers
 * size    -- size of array
 * tfunc   -- pointer to function matching the signature
 *             unsigned char func(int num)
 */
void run_test(int nums[], int size, p_testf tfunc){
	int i;
	
	printf("--------------------------------------\n");

	for (i=0; i < size; i++){
		if (tfunc(i) == TRUE)
			printf("%i ", nums[i]);
	}

	printf("\nTest Unit Completed.\n");
}

/**
 * Prompt the user with an arbitrary binary
 * question. Automatically follows the question
 * specified with [Y/N], returning 1 (TRUE) on 
 * affirmative, and 0 (FALSE) on negative.
 *
 * question  - Question to ask, ex. "Continue?"
 */
unsigned char prompt_yn(const char *question){
	int c; /* getchar() must be stored in a type
		  larger than char, to allow for EOF */
	
	while(TRUE) {
		printf("%s [y/n] ", question);

		/* Damn you, buffered io */
		while((c = getchar()) != EOF){
			if(c != '\n')
				putchar(c);
		
		switch(c){
			case 'y':
			case 'Y':
				return TRUE;
			case 'n':
			case 'N':
				return FALSE;
			default:
				printf("Please answer [Y]es or [N]o\n");
				break;
		}
	}
}

/**
 * Test if number is lower than the value
 * defined by the LESSTHANVAL magic number.
 * Returns 1(TRUE) on success, 0(FALSE) on
 * failure.
 *
 * Intended to be passed as a pointer to the
 * run_test() function.
 *
 * num -- integer to test
 */
unsigned char test_is_lt_spec(int num){
	/* Ternary operator, shorthand */
	return (num < LESSTHANVAL) ? TRUE : FALSE;
}

/**
 * Test if integer is odd.
 * Returns 1(TRUE) on success, 0(FALSE) on
 * failure.
 *
 * Intended to be passed as a pointer to the
 * run_test() function.
 *
 * num -- integer to test
 */
unsigned char test_is_odd(int num){
	/* Ternary operator, shorthand */
	return (!(num % 2)) ? TRUE : FALSE;
}