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import java.util.Arrays;
/**
*
*
* Simple class for benchmarking some sorting algorithms
*/
public class BenchMarker {
final static int ARRAY_SIZE = 100_000;
/**
* Sorts an unsorted list of integers by using insertion sort
* @param list an array of integers.
*/
static void insertionSort(int[] list) {
int itemsSorted;
for(itemsSorted = 1; itemsSorted < list.length; itemsSorted++) {
int temp = list[itemsSorted];
int loc = itemsSorted - 1;
while(loc >= 0 && list[loc] > temp) {
list[loc + 1] = list[loc];
loc = loc - 1;
}
list[loc + 1] = temp;
}
}
/**
* Sorts an unsorted list of integers by using selection sort
* @param list an array of integers.
*/
static void selectionSort(int [] list) {
for(int first = 0; first < list.length; first++) {
int smallestLoc = first;
for(int j = first + 1; j < list.length; j++) {
if(list[j] < list[smallestLoc]) {
smallestLoc = j;
}
}
int temp = list[smallestLoc];
list[smallestLoc] = list[first];
list[first] = temp;
}
}
public static void main(String[] args) {
int[] firstIntList = new int[ARRAY_SIZE];
int[] secondIntList = new int[ARRAY_SIZE];
int[] thirdIntList = new int[ARRAY_SIZE];
long startTime, runTime;
System.out.println("Creating sample arrays of " + ARRAY_SIZE + " items");
for(int i = 0; i < ARRAY_SIZE; i++) {
int item = (int)(Integer.MAX_VALUE * Math.random());
firstIntList[i] = item;
secondIntList[i] = item;
thirdIntList[i] = item;
}
System.out.println("======================= DONE ===========================");
// Sort using selectionSort sort
System.out.println("Sorting using selection sort");
startTime = System.currentTimeMillis();
selectionSort(firstIntList);
runTime = System.currentTimeMillis() - startTime;
System.out.println("Selection sort completed in: " + runTime + " Milliseconds");
System.out.println("======================= DONE ===========================");
// Sort using insertion sort
System.out.println("Sorting using insertion sort");
startTime = System.currentTimeMillis();
insertionSort(secondIntList);
runTime = System.currentTimeMillis() - startTime;
System.out.println("Insertion sort completed in: " + runTime + " Milliseconds");
System.out.println("======================= DONE ===========================");
// Sort using Arrays.sort()
System.out.println("Sorting using in-built Arrays.sort()");
startTime = System.currentTimeMillis();
Arrays.sort(thirdIntList);
runTime = System.currentTimeMillis() - startTime;
System.out.println("Arrays.sort() sort completed in: " + runTime + " Milliseconds");
System.out.println("======================= DONE ===========================");
}
}
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