chapter 7 exercises

Author: ivanbrennan

ex.7.2.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+
+int main (void)
+{
+	int values[10];
+	int index;
+
+	for ( index = 0; index < 10; ++index )
+		values[index] = 0;
+
+	values[0] = 197;
+	values[2] = -100;
+	values[5] = 350;
+	values[3] = values[0] + values[5];
+	values[9] =
+	values[5] / 10;
+	--values[2];
+
+	for ( index = 0; index < 10; ++index )
+		printf ("values[%i] = %i\n", index, values[index]);
+
+	return 0;
+}

ex.7.3.c

@@ -0,0 +1,30 @@
+#include <stdio.h>
+
+int main (void)
+{
+	int ratingCounters[11], i, response;
+
+	for ( i = 1; i <= 10; ++i )
+		ratingCounters[i] = 0;
+
+	printf ("Enter your responses\n");
+
+	while ( 1 ) {
+		scanf ("%i", &response);
+
+		if ( response == 999 )
+			break;
+		else if ( response < 1 || response > 10 )
+			printf ("Bad response: %i\n", response);
+		else
+			++ratingCounters[response];
+	}
+
+	printf ("\n\nRating    Number of Responses\n");
+	printf ("------ --------------------\n");
+
+	for ( i = 1; i <= 10; ++i )
+		printf ("%4i%14i\n", i, ratingCounters[i]);
+
+	return 0;
+}

ex.7.4.c

@@ -0,0 +1,20 @@
+// Calculate the average of an array of floating-point values
+#include <stdio.h>
+
+int main (void)
+{
+	float values[10] = {
+		0.1, 1.2, 2.3, 3.4, 4.5,
+		5.6, 6.7, 7.8, 8.9, 9.0
+	};
+	int count = sizeof(values) / sizeof(float);
+
+	float sum;
+
+	for ( int i = 0; i < count; i++ )
+		sum += values[i];
+
+	printf ("Average: %.2f\n", sum / count);
+
+	return 0;
+}

ex.7.5.c

@@ -0,0 +1,18 @@
+#include <stdio.h>
+
+int main (void)
+{
+	int numbers[10] = { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+	int i, j;
+
+	for ( j = 0; j < 10; ++j )
+		for ( i = 0; i < j; ++i )
+			numbers[j] += numbers[i];
+
+	for ( j = 0; j < 10; ++j )
+		printf ("%i ", numbers[j]);
+
+	printf ("\n");
+
+	return 0;
+}

ex.7.6.c

@@ -0,0 +1,22 @@
+// Program to generate the first 15 Fibonacci numbers
+#include <stdio.h>
+
+int main (void)
+{
+	int prePrevFibonacci, prevFibonacci, Fibonacci, i;
+
+	prePrevFibonacci = 0;
+	prevFibonacci    = 1;
+
+	printf ("%i\n%i\n", prePrevFibonacci, prevFibonacci);
+
+	for ( i = 0; i < 13; ++i ) {
+		Fibonacci = prePrevFibonacci + prevFibonacci;
+		printf ("%i\n", Fibonacci);
+
+		prePrevFibonacci = prevFibonacci;
+		prevFibonacci    = Fibonacci;
+	}
+
+	return 0;
+}

ex.7.7.c

@@ -0,0 +1,18 @@
+// Use the Sieve of Erastosthenes to generate prime numbers
+#include <stdio.h>
+
+int main (void)
+{
+	const int n = 150;
+	int P[n + 1] = { 0 };
+
+	for ( int i = 2; i <= n; ++i ) {
+		if ( P[i] == 0 )
+			printf ("%i  ", i);
+		for ( int j = 1; i * j <= n; ++j )
+			P[i * j] = 1;
+	}
+	printf ("\n");
+
+	return 0;
+}