chapter 6 exercises

Author: ivanbrennan

ex.6.2.c

@@ -0,0 +1,18 @@
+// Test the divisibility of two use-supplied integers
+
+#include <stdio.h>
+
+int main (void)
+{
+	int value1, value2;
+
+	printf ("Enter two integers\n");
+	scanf  ("%i %i", &value1, &value2);
+
+	if ( value1 % value2 == 0 )
+		printf ("%i is evenly divisible by %i\n", value1, value2);
+	else
+		printf ("%i is not evenly divisible by %i\n", value1, value2);
+
+	return 0;
+}

ex.6.3.c

@@ -0,0 +1,18 @@
+// Divide two use-supplied integers
+
+#include <stdio.h>
+
+int main (void)
+{
+	int value1, value2;
+
+	printf ("Enter two integers\n");
+	scanf  ("%i %i", &value1, &value2);
+
+	if ( value2 != 0 )
+		printf ("%i / %i = %.3f\n", value1, value2, (float) value1 / value2);
+	else
+		printf ("Division by zero\n");
+
+	return 0;
+}

ex.6.4.c

@@ -0,0 +1,49 @@
+// Simple printing calculator
+
+#include <stdio.h>
+
+int main (void)
+{
+	printf ("Begin Calculations\n");
+
+	double	number, accumulator;
+	char	operator = '\0';
+
+	while ( operator != 'E' ) {
+		scanf  ("%lf %c", &number, &operator);
+
+		switch ( operator ) {
+			case '+':
+				accumulator += number;
+				break;
+			case '-':
+				accumulator -= number;
+				break;
+			case '*':
+				accumulator *= number;
+				break;
+			case '/':
+				if ( number != 0 ) {
+					accumulator /= number;
+					break;
+				}
+				else {
+					printf ("Division by zero\n");
+					continue;
+				}
+			case 'S':
+				accumulator = number;
+				break;
+			case 'E':
+				break;
+			default:
+				printf ("Unknown operator\n");
+				continue;
+		}
+
+		printf ("= %f\n", accumulator);
+	}
+	printf ("End of Calculations.\n");
+
+	return 0;
+}

ex.6.5.c

@@ -0,0 +1,27 @@
+// Program to reverse the digits of a number
+
+#include <stdio.h>
+
+int main (void)
+{
+	int number, absolute_value, right_digit;
+
+	printf ("Enter your number.\n");
+	scanf  ("%i", &number);
+
+	absolute_value = ( number < 0 ) ? -number : number;
+
+	do {
+		right_digit = absolute_value % 10;
+		printf ("%i", right_digit);
+		absolute_value /= 10;
+	}
+	while ( absolute_value != 0 );
+
+	if ( number < 0 )
+		printf ("-");
+
+	printf ("\n");
+
+	return 0;
+}

ex.6.6.c

@@ -0,0 +1,59 @@
+// Display digits in English
+
+#include <stdio.h>
+
+int main (void)
+{
+	int number, digit;
+
+	printf ("Type an integer\n");
+	scanf  ("%i", &number);
+
+	int power = 1;
+	while ( number / power > 9 )
+		power *= 10;
+
+	do {
+		digit = number / power;
+		number -= digit * power;
+		power /= 10;
+
+		switch ( digit ) {
+			case 0:
+				printf ("zero ");
+				break;
+			case 1:
+				printf ("one ");
+				break;
+			case 2:
+				printf ("two ");
+				break;
+			case 3:
+				printf ("three ");
+				break;
+			case 4:
+				printf ("four ");
+				break;
+			case 5:
+				printf ("five ");
+				break;
+			case 6:
+				printf ("six ");
+				break;
+			case 7:
+				printf ("seven ");
+				break;
+			case 8:
+				printf ("eight ");
+				break;
+			case 9:
+				printf ("nine ");
+				break;
+		}
+	}
+	while ( number != 0 );
+
+	printf ("\n");
+
+	return 0;
+}

ex.6.7.c

@@ -0,0 +1,25 @@
+// Program to generate a table of prime numbers
+
+#include <stdio.h>
+#include <stdbool.h>
+
+int main (void)
+{
+	int		p, d;
+	bool	isPrime;
+
+	for ( p = 2; p <= 50; p += (p == 2) ? 1 : 2 ) {
+
+		isPrime = true;
+
+		for ( d = 3; isPrime && d < p; d += 2 )
+			if ( p % d == 0 )
+				isPrime = false;
+
+		if ( isPrime != false )
+			printf ("%i  ", p);
+	}
+
+	printf ("\n");
+	return 0;
+}