recursionDriver.java

public class recursionDriver
{
 public static void main(String[] args)
 {
     /*
     * Count 
     * 1. Number of legs 10 elephant have
     * 2. Number of students in a school if each
     * class has 20 students and there are 12 rooms
     * 3. Number of fingers if there are 8 people
     * 4. Find the sum of odd numbers from 0 to N
     * 5. Find the sum of even numbers from 0 to N
    */ 
     int counted=0;
     // Task 1.
     System.out.println(count1(10));
     System.out.println(count2(12));
     System.out.println(count3(8));
     System.out.println(count4(13));
     System.out.println(count5(12));
    }
 public static int count1(int a)
 {
     if(a==0)
     {
         return 0;
     }
     return 4+count1(a-1);
 }
 public static int count2(int a)
 {
     if(a==0)
     {
         return 0;
     }
     return 20+count2(a-1);
 }
 public static int count3(int a)
 {
     if(a==0)
     {
         return 0;
     }
     return 10+count3(a-1);
 }
 public static int count4(int a)
 {
     if(a<=0)
     {
         return 0;
     }
     return a+count4(a-2);
 }
 public static int count5(int a)
 {
     if(a<=0)
     {
         return 0;
     }
     return a+count5(a-2);
 }
}