归并排序

package com.lin.test;

public class Sort {

	static void merge(int a[], int first, int mid, int last, int[] temp) {
		int i = first, j = mid + 1, k = 0;
		while (i <= mid && j <= last) {
			if (a[i] <= a[j]) {
				temp[k++] = a[i++];
			} else {
				temp[k++] = a[j++];
			}

		}
		while (i <= mid) {
			temp[k++] = a[i++];
		}
		while (j <= last) {
			temp[k++] = a[j++];
		}
		for (i = 0; i < k; i++) {
			a[first + i] = temp[i];
		}
	}

	static void mergeSort(int a[], int first, int last, int temp[]) {
		if (first < last) {
			int mid = (first + last) / 2;
			mergeSort(a, first, mid, temp);
			mergeSort(a, mid + 1, last, temp);
			merge(a, first, mid, last, temp);
		}
	}

	public static void main(String[] args) {
		int a[] = { 3, 2, 5, 7, 8, 9, 4, 1, 0, 4, 6 };
		int[] temp = new int[a.length];
		mergeSort(a, 0, a.length - 1, temp);
		for (int i : a) {
			System.out.print(i + " ");
		}
	}
}