插入排序，归并排序

package org.sz.sort;import java.util.Arrays;/** * 排序工具类 */public class SortUtil {    /**     * 插入排序     * compareTo需要消费一个T所以<? super T>     * 过程类似从小到大整理手中的扑克     */public static <T extends Comparable<? super T>>         void insertionSort(T[] a) {int j;for (int i = 1; i < a.length; i++) {T tmp = a[i];for (j = i; j > 0; j--) {if (tmp.compareTo(a[j -1]) < 0) {a[j] = a[j -1];a[j -1] = tmp;}}}    }    /**     * 归并排序     */private static <T extends Comparable<? super T>>     void mergeSort(T[] a, T[] tmp, int left, int right) {if (left < right) {int center = (left + right) / 2;mergeSort(a, tmp, left , center);mergeSort(a, tmp, center + 1, right);merge(a, tmp, left, center + 1, right);}}private static <T extends Comparable<? super T>>    void merge(T[] a, T[] tmp, int leftPos, int rightPos, int rightEnd) {int leftEnd = rightPos - 1;int tmpPos = leftPos;int numElements = rightPos - leftPos + 1;while(leftPos <= leftEnd && rightPos <= rightEnd) {if(a[leftPos].compareTo(a[rightPos]) < 0)tmp[tmpPos++] = a[leftPos++]; else tmp[tmpPos++] = a[rightPos++]; }while(leftPos <= leftEnd) {tmp[tmpPos++] = a[leftPos++];}while(rightPos <= rightEnd) {tmp[tmpPos++] = a[rightPos++];}for(int i = 0; i < numElements; i++, rightEnd--) {a[rightEnd] = tmp[rightEnd];}}public static void main(String[] args) {Subject[] a = {new Subject(20), new Subject(54), new Subject(50)};insertionSort(a);System.out.println(Arrays.deepToString(a));}static class Subject implements Comparable<Subject> {        private int score;        public Subject(int score) {        this.score = score;        }@Overridepublic int compareTo(Subject o) {if (this.score > o.score) {return 1;} else if (this.score < o.score) {return -1;} else {return 0;}}@Overridepublic String toString() {return "分数" + this.score;}}}