// CSE 142, Summer 2008, Helene Martin
 
// Array parameter and return practice.

import java.util.*;

public class Practice {
	public static void main(String[] args) {
		int[] nums0 = {3, 5, 9, 5};
		int count = count(nums0, 5);
		System.out.println("5 count: " + count);
		
		int[] nums = {4, -2, 6, 23, -5, 4, 6, 4};
		System.out.println(Arrays.toString(nums));
		
		replace(nums, 4, 5);
		// Should result in {5, -2, 6, 23, -5, 5, 6, 5}
		System.out.println(Arrays.toString(nums));
		
		int[] nums2 = {1, 0 , -1, -1, 0 , 1, -1};
		System.out.println(Arrays.toString(nums2));
		
		replace(nums2, -1, 0);
		// Should result in {1, 0, 0, 0, 0, 1, 0}		
		System.out.println(Arrays.toString(nums2));
	}
	
	// Replaces all instances of val1 in array with val2
	// No need to return because of reference semantics
	public static void replace(int[] array, int val1, int val2) {
		for(int i = 0; i < array.length; i++) {
			if(array[i] == val1) {
				array[i] = val2;
			}
		}
	}
	
	// Counts and returns occurences of target in array.
	public static int count(int[] array, int target) {
		int counter = 0;
		
		for (int i = 0; i < array.length; i++) {
			if(array[i] == target) {
				counter++;
			}
		}
		return counter;
	}
}