package disorder_List;import java.util.ArrayList;
import java.util.Collections;
import java.util.Random; public class TestDisorder { static public int cmpcnt = 0; public static void main(String[] args) { testFramework(); } public static int partion(ArrayList<Integer> A,int low,int high){int pivotkey=A.get(low);while(low<high){while(low<high&&A.get(high)>=pivotkey)high--;A.set(low, A.get(high));cmpcnt++;while(low<high&& A.get(low)<pivotkey)low++;A.set(high, A.get(low));cmpcnt++;}cmpcnt++;A.set(low, pivotkey);return low;}public static int findMinK(ArrayList<Integer> array, int k, int l, int r) { // Implement here if(l<=r){int pivotloc=partion(array, l, r);if(pivotloc==k-1){return array.get(pivotloc);}else if(pivotloc<(k-1)){return findMinK(array, k,pivotloc+1,r);}else{return findMinK(array, k,l,pivotloc-1);}}else{return -1;}} public static int findMinK(ArrayList<Integer> array, int k){ Collections.sort(array); return array.get(k-1); } private static void testFramework() { ArrayList<Integer> a = new ArrayList<Integer>(); for (int j=2;j<8;j++){ a.clear(); for (int i=0;i<(int)Math.pow(10, j);i++){ a.add(i); } System.out.println("nn"+a.size()+" Elementsnn"); double slow=0; double fast=0; for (int i = 0; i < 2; i++) { cmpcnt = 0; Collections.shuffle(a); int k = (int)(Math.random()*(Math.pow(10, j)-1))+1; System.out.println("test run number: " + i + " find: " + k); long start = System.currentTimeMillis(); int resulta = findMinK(a, k, 0, a.size()-1); long end = System.currentTimeMillis(); long smarttime=(end-start); fast = fast + smarttime; System.out.println("SMART ALGO t --- time in ms: " + smarttime + " comparisons: " + cmpcnt); start = System.currentTimeMillis(); int resultb=findMinK(a, k); end = System.currentTimeMillis(); long slowtime = (end-start); System.out.println("WITH SORTING t --- time in ms: " + slowtime); slow = slow + slowtime; }            System.out.println("sorting (="+slow+"ms) is " +slow/fast + " times slower than smart algo (="+fast+"ms)"); } }
}