I dette eksempel lærer vi at implementere hurtig sorteringsalgoritme i Java.
For at forstå dette eksempel skal du have kendskab til følgende Java-programmeringsemner:
- Java-metoder
- Java til Loop
- Java Arrays
Eksempel: Java-program til implementering af hurtig sorteringsalgoritme
// Quick sort in Java import java.util.Arrays; class Main ( // divide the array on the basis of pivot int partition(int array(), int low, int high) ( // select last element as pivot int pivot = array(high); // initialize the second pointer int i = (low - 1); // Put the elements smaller than pivot on the left and // greater than pivot on the right of pivot for (int j = low; j = pivot) if (array(j) <= pivot) ( // increase the second pointer if // smaller element is swapped with greater i++; int temp = array(i); array(i) = array(j); array(j) = temp; ) ) // put pivot in position // so that element on left are smaller // element on right are greater than pivot int temp = array(i + 1); array(i + 1) = array(high); array(high) = temp; return (i + 1); ) void quickSort(int array(), int low, int high) ( if (low < high) ( // Select pivot position and put all the elements smaller // than pivot on the left and greater than pivot on right int pi = partition(array, low, high); // sort the elements on the left of the pivot quickSort(array, low, pi - 1); // sort the elements on the right of pivot quickSort(array, pi + 1, high); ) ) // Driver code public static void main(String args()) ( // create an unsorted array int() data = ( 8, 7, 2, 1, 0, 9, 6 ); int size = data.length; // create an object of the Main class Main qs = new Main(); // pass the array with the first and last index qs.quickSort(data, 0, size - 1); System.out.println("Sorted Array: "); System.out.println(Arrays.toString(data)); ) )
Udgang 1
Usorteret matrix: (8, 7, 2, 1, 0, 9, 6) Sorteret matrix: (0, 1, 2, 6, 7, 8, 9)
Her sorteres elementerne i arrayet i stigende rækkefølge. Hvis vi vil sortere elementerne i faldende rækkefølge, kan vi inden i partition()metodens for-løkke ændre koden som:
// the less than sign is changed to greater than if (array(j)>= pivot) (
Hvis du vil lære mere om hurtig sorteringsalgoritmen, skal du besøge hurtig sorteringsalgoritme.
