01204212/recur

countIf

<syntexhighlight lang="java"> package adt_ex_w6_recur;

import java.util.Iterator; import java.util.LinkedList; import java.util.ListIterator;

public class Main {

   static private int countIfLoop(LinkedList<Integer> list, int target) {
       ListIterator<Integer> ii = list.listIterator();
       int count = 0;
       while(ii.hasNext()) {
           if(ii.next() == target) {
               count++;
           }
       }
       return count;
   }
   
   static private int countIf(LinkedList<Integer> list, int target) {
       ListIterator<Integer> ii = list.listIterator();
       return countIf0(ii,target);
   }
   
   static private int countIf0(ListIterator<Integer> ii, int target) {
       // write your code here
       return 0;
   }

   static private int findSize0(ListIterator<Integer> ii) {
       if(! ii.hasNext()) {
           return 0;
       } else {
           ii.next();
           int k = findSize0(ii);
           return k + 1;
       }
   }

   public static void main(String[] args) {
       LinkedList<Integer> list = new LinkedList<Integer>();
       
       list.add(10); list.add(200); list.add(15);
       list.add(11); list.add(200); list.add(15);
       list.add(12); list.add(201); list.add(15);
       list.add(13); list.add(200); list.add(15);

       System.out.println(countIf(list,10));
       System.out.println(countIf(list,15));
       System.out.println(countIf(list,20));
       System.out.println(countIf(list,200));
   }

   private static void printList(LinkedList<Integer> list) {
       Iterator<Integer> i = list.iterator();
       while(i.hasNext()) {
           System.out.print("" + i.next() + " ");
       }
       System.out.println();
   }

} </syntaxhighlight>