KthLargestElement.java

package com.learning.leet.strsarrs;

import java.util.Arrays;

/**
 * Created by sargonbenjamin on 6/19/19.
 * https://leetcode.com/problems/kth-largest-element-in-an-array/
 */
public class KthLargestElement {
    public static void main(String args[]){
        //int[] testArr = {3,2,3,1,2,4,5,5,6};
        int[] testArr = {3,2,1,5,6,4};
        KthLargestElement kth = new KthLargestElement();
        int out = kth.findKthLargest(testArr, 2);
        System.out.println("hi");
    }

    //why is this method faster?
    public int findKthLargestEasy(int[] nums, int k) {
        if(nums==null || nums.length==0)return 0;

        Arrays.sort(nums);
        return nums[nums.length-k];
    }

    //why is this method slower?
    //this bubble sorts until we sort to the kth element
    public int findKthLargest(int[] nums, int k) {
        if(nums==null || nums.length==0)return 0;

        int loopCount = 0;
        while(loopCount<k){
            for(int i = 1; i<nums.length-loopCount; i++){
                if(nums[i-1]>nums[i]){
                    int temp = nums[i-1];
                    nums[i-1] = nums[i];
                    nums[i] = temp;
                }
            }
            loopCount++;
        }
        return nums[nums.length-k];
    }
}