Dalam contoh ini, kita akan belajar mengimplementasikan algoritma sort cepat di Java.
Untuk memahami contoh ini, anda harus mempunyai pengetahuan mengenai topik pengaturcaraan Java berikut:
- Kaedah Java
- Java untuk Gelung
- Susunan Java
Contoh: Program Java untuk Melaksanakan Algoritma Urutan Pantas
// 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)); ) )
Keluaran 1
Array Tidak Diurutkan: (8, 7, 2, 1, 0, 9, 6) Susun Susun: (0, 1, 2, 6, 7, 8, 9)
Di sini, elemen larik disusun mengikut urutan menaik. Sekiranya kita ingin menyusun elemen dalam urutan menurun, maka di dalam kaedah loop partition(), kita boleh menukar kodnya sebagai:
// the less than sign is changed to greater than if (array(j)>= pivot) (
Sekiranya anda ingin mengetahui lebih lanjut mengenai algoritma urutan cepat, kunjungi Algoritma Urut Pantas.
