参考以下程序在 Java 中执行归并排序。
public class MyMergeSort {
void merge(int arr[], int beg, int mid, int end) {
int l = mid - beg + 1;
int r = end - mid;
intLeftArray[] = new int[l];
intRightArray[] = new int[r];
for (int i = 0; i < l; ++i) {
LeftArray[i] = arr[beg + i];
}
for (int j = 0; j < r; ++j) {
RightArray[j] = arr[mid + 1 + j];
}
int i = 0, j = 0;
int k = beg;
while (i < l && j < r) {
if (LeftArray[i] <= RightArray[j]) {
arr[k] = LeftArray[i];
i++;
} else {
arr[k] = RightArray[j];
j++;
}
k++;
}
while (i < l) {
arr[k] = LeftArray[i];
i++;
k++;
}
while (j < r) {
arr[k] = RightArray[j];
j++;
k++;
}
}
void sort(int arr[], int beg, int end) {
if (beg < end) {
int mid = (beg + end) / 2;
sort(arr, beg, mid);
sort(arr, mid + 1, end);
merge(arr, beg, mid, end);
}
}
public static void main(String args[]) {
intarr[] = {90
,23,101,45,65,23,67,89,34,23};
MyMergeSort ob = new MyMergeSort();
ob.sort(arr, 0, arr.length - 1);
System.out.println("\nSorted array");
for (int i = 0; i < arr.length; i++) {
System.out.println(arr[i] + "");
}
}
}
运行结果:
Sorted array
23
23
23
34
45
65
67
89
90
101