java排序 内部排序 选择排序

package com.basic.sort;public class BasicSort {public static void main(String argvs[]) {int test[] = {3,1,2,5,4,3};//choose s = new choose(test);//s.sort();//s.print();heap h = new heap(test);h.sort();h.print();}}/** * 选择排序：内部排序中的直接选择排序  时间复杂度O(n^2) */class choose {private int[] array;public choose(int[] arr) {this.array = arr;}public void sort() {for(int i = 0; i < this.array.length; i++) {int lowindex = i;int tmp = this.array[i];for(int j = i + 1; j < this.array.length; j++) {if (tmp > this.array[j]) {tmp = this.array[j];lowindex = j;}}this.array[lowindex] = this.array[i];this.array[i] = tmp;}}public void print() {for (int i = 0; i < this.array.length; i++) {System.out.println(this.array[i]);}}}/** * 堆排序：内部排序中的选择排序  时间复杂度O(nLogn) */class heap {private int[] array;public heap(int[] arr) {this.array = arr;}public void sort() {for(int i = 0; i < this.array.length-1; i++) {buildmaxheap(this.array, this.array.length-1-i);swap(this.array, 0, this.array.length-1-i);}}private void buildmaxheap(int[] arr, int lastindex) {for (int i = (lastindex-1)/2; i >= 0; i--) {int k = i;//左孩子存在则不断比较while(k*2+1 <= lastindex) {//获取当前节点的左孩子的数组索引int big = 2 * k + 1;if (big < lastindex) {//若右孩子的值大于左孩子的值则选择右孩子来和当前节点交互if (arr[big] < arr[big+1]) {big++;}}if (arr[k] < arr[big]) {swap(arr, k, big);//保存需要继续比较的当前节点，比如在根节点调整的情况下，孩子的孩子可能也需要再调整k = big;} else {break;}}}}private void swap(int[] arr, int i, int j) {int tmp = arr[i];arr[i] = arr[j];arr[j] = tmp;}public void print() {for (int i = 0; i < this.array.length; i++) {System.out.println(this.array[i]);}}}