move exercises, lecture examples, labs into subfolders

Exercises/C9/ex4.c

@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+	int age = 1; // Declare variable and initialise to 1
+
+	do {
+
+	printf ("\nPlease enter your age: ");
+	scanf("%d", &age);
+	printf ("You are %d years old\n", age);
+
+	if (age == 18 || age == 21) {
+		printf("You have come of age\n");
+	}
+
+	// Code  now goes back and repeats the test with the value of age just entered
+	} while ( age != 0); // Loop as long as age is not zero
+	return 0; // Exit code
+}