move exercises and lectures into subfolders

Exercises/C8/ex2.c

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+#include <stdio.h>
+
+int main() {
+	int input;
+
+	printf("Enter an integer: ");
+	scanf("%d", &input);
+
+	if (input >= 0 && input <= 10) {
+		printf("The number is in range\n");
+	}
+
+	return 0;
+}

Exercises/C8/ex3.c

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+#include <stdio.h>
+
+int main() {
+	int input;
+
+	printf("Enter an integer: ");
+	scanf("%d", &input);
+
+	if (!(input >= 0 && input <= 10)) {
+		printf("The number is not in range\n");
+	}
+
+	return 0;
+}

Exercises/C8/ex4.c

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+#include <stdio.h>
+
+int main() {
+	int age;
+
+	printf("Enter your age: ");
+	scanf("%d", &age);
+
+	// c only matches one branch so don't need to specify lower limits of each age range
+	if ( age <= 0 ) {
+		printf("Still a baby\n");
+	} else if ( age <= 12 ) {
+		printf("The junior years\n");
+	} else if ( age < 20 ) {
+		printf("Teenage years\n");
+	} else {
+		printf("Downhill all the way now!\n");
+	}
+
+	return 0;
+}

Exercises/C8/ex7.c

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+#include <stdio.h>
+#include <math.h>
+
+int main() {
+	int rc; // used to check return codes of scanf
+	float radius, height;
+
+	printf("Enter radius: ");
+	rc = scanf("%f", &radius);
+	// scanf returns number of scanned items. If input is invalid then 0 values will have been scanned.
+	if (rc != 1) {
+		printf("Please enter an positive real integer or decimal\n");
+		return 1;
+	}
+
+	printf("Enter height: ");
+	rc = scanf("%f", &height);
+	// scanf returns number of scanned items. If input is invalid then 0 values will have been scanned.
+	if (rc != 1) {
+		printf("Please enter an positive real integer or decimal\n");
+		return 1;
+	}
+
+	printf("Surface area: %f\n", 2*M_PI*radius*radius + 2*M_PI*radius*height);
+}

Exercises/C8/if_example.c

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+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+	// Declare some variables
+	int  a = 7, b=6;
+
+	printf("Enter a value for a: ");
+	scanf("%d", &a);
+	printf("Enter a value for b: ");
+	scanf("%d", &b);
+
+	// A single line of code conditional on the value of a
+	if ( a == 7 )
+	   printf ("The value of a is 7 - so I will do this\n");
+	   
+	// Multiple lines of code conditional on b not equalling 4
+	// so then need to be placed inside { and }
+	if ( b != 4 )
+	{
+	   printf ("The value of b is not 4\n");
+	   printf ("So I will do multiple tasks\n");
+	}
+	   
+	return 0;   // Exit from main
+}

Exercises/C8/switch_example_1.c

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+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+    // Declare some variables
+    int a = 1;
+    switch ( a )
+    {
+    case 0 :
+        printf ("Sunday\n");
+        break ; // end of the lines of code to execute
+
+    case 1:
+        printf ("Monday\n");
+        break ; // end of the lines of code to execute
+
+    case 2:
+        printf ("Tuesday\n");
+        break ; // end of the lines of code to execute
+
+    // etc...
+
+    default: // If no case is met (OPTIONAL)
+        printf ("\nThe value supplied is out of range\n");
+
+    }
+    return 0;
+}

Exercises/C8/switch_example_2.c

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+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+	// Declare some variables
+	int a = 1;
+	switch ( a )
+	{
+	case 1 :
+	case 2 : 
+	case 3 : 
+		// Code to do if a is 1, 2 or 3
+	break ; // end of the lines of code to execute
+
+	case 4:
+	case 5:
+		// Code to do if a is 4 or 5
+		break ; // end of the lines of code to execute
+
+	default: // If no case is met (OPTIONAL)
+		// Code to do if no case is met
+	}
+	return 0;
+}

Exercises/C8/switch_example_3.c

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+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+    // Declare some variables
+    int a = 1;
+    switch ( a )
+    {
+    case 1 :
+        printf ("This is case 1\n");
+    case 2 :
+        printf ("This is case 2\n");
+    case 3 :
+        printf ("This is case 3\n");
+        break ; // end of the lines of code to execute
+
+    default: // If no case is met
+        printf ("This default case\n");
+        // Code to do if no case is met
+    }
+    return 0;
+}