合并算法

public class MergeSort {public static void mergeSort(int [] list){if (list.length > 1){int [] firstHalf = new int[list.length / 2];System.arraycopy(list, 0, firstHalf, 0, list.length / 2);mergeSort(firstHalf);//merge sort the second halfint secondHalfLength = list.length - list.length / 2;int[] secondHalf = new int [secondHalfLength];System.arraycopy(list, list.length / 2, secondHalf, 0, secondHalfLength);mergeSort(secondHalf);//Merge firstHalf with second halfint[] temp = merge(firstHalf,secondHalf);System.arraycopy(temp, 0, list, 0, temp.length);}}/** Merge two sorted lists*/private static int [] merge(int[] list1,int [] list2){int [] temp = new int[list1.length + list2.length];int current1 = 0; //Current index in list1int current2 = 0; //Current index in list2int current3 = 0; //Current index in list3while (current1 < list1.length && current2 < list2.length ) {if (list1[current1] < list2[current2]) {temp[current3++] = list1[current1++];}else{temp[current3++] = list2[current2++];}}while (current1 < list1.length ) {temp[current3++] = list1[current1++]; }while (current2 < list2.length ) {temp[current3++] = list2[current2++]; }return temp;}public static void main(String[] args) {int[] list = {2,3,2,5,6,1,-2,3,14,12};mergeSort(list);for (int i = 0; i < list.length; i++) {System.out.print("  "+list[i]);}}}