MySort.java
package cn.edu.wtu.sort;public class MySort {/** * 冒泡排序 * * @param a */public static void bubble(int a[]) {for (int i = 0; i < a.length; ++i) {for (int j = 1; j < a.length - i; ++j) {if (a[j] < a[j - 1]) {a[j] ^= a[j - 1];a[j - 1] ^= a[j];a[j] ^= a[j - 1];}}}}/** * 插入排序，认为第一个数是有序的，依次插入其他数 使用插入排序数组第零号最好不要存储数据 * * @param a */public static void insertSort(int a[]) {for (int i = 1; i < a.length; ++i) {int tmp = a[i], j;for (j = i; j > 0 && tmp < a[j - 1]; --j) {a[j] = a[j - 1];}a[j] = tmp;}}/** * 插入排序 第零号元素不存数据 * * @param a */public static void insertSort1(int a[]) {for (int i = 2, j; i < a.length; ++i) {a[0] = a[i];for (j = i; a[0] < a[j - 1]; --j) {a[j] = a[j - 1];}a[j] = a[0];}}/** * 快速排序 * * @param a */public static void QSort(int a[]) {QSort(a, 0, a.length - 1);}private static void QSort(int a[], int low, int high) {if (low < high) {int pivot = Partation(a, low, high);QSort(a, low, pivot - 1);QSort(a, pivot + 1, high);}}private static int Partation(int[] a, int low, int high) {while (low < high) {while (low < high && a[low] <= a[high]) {--high;}/** 交换两数 此处不能使用位运算 因为当low与high相等时a[low]=a[high]=0 */int tmp = a[low];a[low] = a[high];a[high] = tmp;while (low < high && a[low] <= a[high]) {++low;}tmp = a[low];a[low] = a[high];a[high] = tmp;}return low;}/** * 希尔排序 * * @param a */public static void shellSort(int a[]) {int b[] = { 5, 3, 1 };for (int i = 0; i < b.length; ++i) {shellSort(a, b[i]);}}private static void shellSort(int a[], int dk) {int i, j;for (i = dk; i < a.length; i += dk) {int tmp = a[i];for (j = i - dk; j >= 0 && a[j] > tmp; j -= dk) {a[j + dk] = a[j];}a[j + dk] = tmp;}}/** * 堆排序 * * @param a */public static void heapSort(int a[]) {for (int i = a.length / 2 - 1; i >= 0; --i) {// 构造初始堆（构建一个完全二叉树，保证所有的父结点都比它的孩子结点数值大heapAdjust(a, i, a.length - 1);}// 每次交换第一个和最后一个元素，输出最后一个元素（最大值），然后把剩下元素重新调整为大根堆。// 当输出完最后一个元素后，这个数组已经是按照从小到大的顺序排列了。for (int i = a.length - 1; i > 0; --i) {a[0] ^= a[i];a[i] ^= a[0];a[0] ^= a[i];heapAdjust(a, 0, i);}}private static void heapAdjust(int a[], int i, int n) {int child = 2 * i + 1;int tmp = a[i];while (child < n) {if (child < n - 1 && a[child] < a[child + 1]) {++child;}if (tmp >= a[child]) {break;}a[i] = a[child];i = child;child = 2 * child + 1;}a[i] = tmp;}/** * 归并排序 * * @param a */public static void mergeSort(int a[]) {int tmp[] = new int[a.length];mergeSort(a, 0, a.length - 1, tmp);}private static void mergeSort(int a[], int first, int last, int tmp[]) {if (first < last) {int mid = (first + last) / 2;mergeSort(a, first, mid, tmp);mergeSort(a, mid + 1, last, tmp);mergeArray(a, first, mid, last, tmp);}}/* 数组合并 */private static void mergeArray(int a[], int first, int mid, int last, int tmp[]) {int i = first;int j = mid + 1;int k = 0;while (i <= mid && j <= last) {if (a[i] < a[j]) {tmp[k++] = a[i++];} else {tmp[k++] = a[j++];}}while (i <= mid) {tmp[k++] = a[i++];}while (j <= last) {tmp[k++] = a[j++];}for (i = 0; i < k; ++i) {a[first + i] = tmp[i];}}/** * 基数排序 * * @param a */public static void radixSort(int a[]) {int n = getMaxLength(a);int i = 1;while (n-- != 0) {sortByDigit(a, i);i *= 10;}}/* 根据digit位排序，这里使用的是冒泡，可改用其它 */private static void sortByDigit(int a[], int digit) {for (int i = 0; i < a.length; ++i) {for (int j = 1; j < a.length - i; ++j) {if (getDigit(a[j - 1], digit) > getDigit(a[j], digit)) {a[j - 1] ^= a[j];a[j] ^= a[j - 1];a[j - 1] ^= a[j];}}}}/* 得到数组的最大位数 */private static int getMaxLength(int a[]) {int max = 0;for (int i = 0; i < a.length; ++i) {if (max < getLength(a[i])) {max = getLength(i);}}return max;}/* 得到位数 一种数学方法得到 一种利用java类型转换得到 */private static int getLength(int n) {int m = 0;while (n % 10 != 0) {m++;n /= 10;}return m;// return String.valueOf(n).length();}/* 得到digit位上的数字 */private static int getDigit(int n, int digit) {return n / digit % 10;}/* * 选择排序 */public static void selectSort(int a[]){for( int i = 0 ; i < a.length; ++i ){int min = a[i];int index = i ;for( int j = i+1 ; j < a.length; ++j){if(min >a[j]){min = a[j];index = j;}}a[index] = a[i];a[i] = min;}}}
Utils.java
package cn.edu.wtu.utils;import java.util.Random;public class Utils {//得到一个随机数组，public static int [] getArray(int n){int a[] = new int[n];Random ran=new Random();for( int i = 0 ; i < n ; ++i ){a[i] = ran.nextInt(100); //产生100以内的整数}return a;}public static void print( int a[] ){for( int i=0; i<a.length; ++i){System.out.print(a[i]+" ");}System.out.println(); }}
Test.java
package cn.edu.wtu.test;import java.util.Arrays;import cn.edu.wtu.sort.MySort;import cn.edu.wtu.utils.Utils;public class Test {public static void main(String[] args) {int n = 20; //产生数组的大小int a[] = Utils.getArray(n);Utils.print(a);//直接调用Arrays的sort方法排序Arrays.sort(a);//MySort.bubble(a);//MySort.insertSort(a);//MySort.QSort(a);//MySort.shellSort(a);//MySort.heapSort(a);//MySort.mergeSort(a);//MySort.radixSort(a);//MySort.selectSort(a);Utils.print(a);}}
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