五种比较高效常用的排序算法

代码]选择排序     

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 public class SelectionSort {      public void selectionSort( int [] array) {          int temp;          for ( int i = 0 ; i < array.length - 1 ; i++) {              for ( int j = i + 1 ; j <= array.length - 1 ; j++) { // 第i个和第j个比较j可以取到最后一位,所以要用j<=array.length-1                  if (array[i] > array[j]) { // 注意和冒泡排序的区别,这里是i和j比较。                      temp = array[i];                      array[i] = array[j];                      array[j] = temp;                  }              }              // 打印每趟排序结果              for ( int m = 0 ; m <= array.length - 1 ; m++) {                  System.out.print(array[m] + "\t" );              }              System.out.println();          }      }          public static void main(String[] args) {          SelectionSort selectionSort = new SelectionSort();          int [] array = { 5 , 69 , 12 , 3 , 56 , 789 , 2 , 5648 , 23 };          selectionSort.selectionSort(array);          for ( int m = 0 ; m <= array.length - 1 ; m++) {              System.out.print(array[m] + "\t" );          }      } }

2. [代码]插入排序     

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 public class InsertSort {      public void insertSort( int [] array, int first, int last) {          int temp, i, j;          for (i = first + 1 ; i <= last - 1 ; i++) { // 默认以第一个数为有序序列,后面的数为要插入的数。              temp = array[i];              j = i - 1 ;              while (j >= first && array[j] > temp) { // 从后进行搜索如果搜索到的数小于temp则该数后移继续搜索,直到搜索到小于或等于temp的数即可                  array[j + 1 ] = array[j];                  j--;              }              array[j + 1 ] = temp;              // 打印每次排序结果              for ( int m = 0 ; m <= array.length - 1 ; m++) {                  System.out.print(array[m] + "\t" );              }              System.out.println();          }      }          public static void main(String[] args) {          InsertSort insertSort = new InsertSort();          int [] array = { 5 , 69 , 12 , 3 , 56 , 789 , 2 , 5648 , 23 };          insertSort.insertSort(array, 0 , array.length); // 注意此处是0-9而不是0-8          for ( int i = 0 ; i <= array.length - 1 ; i++) {              System.out.print(array[i] + "\t" );          }      } }

3. [代码]归并排序     

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 public class MergeSortTest {      public void sort( int [] array, int left, int right) {          if (left >= right)              return ;          // 找出中间索引          int center = (left + right) / 2 ;          // 对左边数组进行递归          sort(array, left, center);          // 对右边数组进行递归          sort(array, center + 1 , right);          // 合并          merge(array, left, center, right);          // 打印每次排序结果          for ( int i = 0 ; i < array.length; i++) {              System.out.print(array[i] + "\t" );          }          System.out.println();          }          /**       * 将两个数组进行归并,归并前面2个数组已有序,归并后依然有序       *       * @param array       *            数组对象       * @param left       *            左数组的第一个元素的索引       * @param center       *            左数组的最后一个元素的索引,center+1是右数组第一个元素的索引       * @param right       *            右数组最后一个元素的索引       */      public void merge( int [] array, int left, int center, int right) {          // 临时数组          int [] tmpArr = new int [array.length];          // 右数组第一个元素索引          int mid = center + 1 ;          // third 记录临时数组的索引          int third = left;          // 缓存左数组第一个元素的索引          int tmp = left;          while (left <= center && mid <= right) {              // 从两个数组中取出最小的放入临时数组              if (array[left] <= array[mid]) {                  tmpArr[third++] = array[left++];              } else {                  tmpArr[third++] = array[mid++];              }          }          // 剩余部分依次放入临时数组(实际上两个while只会执行其中一个)          while (mid <= right) {              tmpArr[third++] = array[mid++];          }          while (left <= center) {              tmpArr[third++] = array[left++];          }          // 将临时数组中的内容拷贝回原数组中          // (原left-right范围的内容被复制回原数组)          while (tmp <= right) {              array[tmp] = tmpArr[tmp++];          }      }          public static void main(String[] args) {          int [] array = new int [] { 5 , 69 , 12 , 3 , 56 , 789 , 2 , 5648 , 23 };          MergeSortTest mergeSortTest = new MergeSortTest();          mergeSortTest.sort(array, 0 , array.length - 1 );          System.out.println( "排序后的数组:" );          for ( int m = 0 ; m <= array.length - 1 ; m++) {              System.out.print(array[m] + "\t" );          }      } }

4. [代码]希尔排序     

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 public class ShellSort {      public void shellSort( int [] array, int n) {          int i, j, gap;          int temp;          for (gap = n / 2 ; gap > 0 ; gap /= 2 ) { // 计算gap大小              for (i = gap; i < n; i++) { // 将数据进行分组                  for (j = i - gap; j >= 0 && array[j] > array[j + gap]; j -= gap) { // 对每组数据进行插入排序                      temp = array[j];                      array[j] = array[j + gap];                      array[j + gap] = temp;                  }                  // 打印每趟排序结果                  for ( int m = 0 ; m <= array.length - 1 ; m++) {                      System.out.print(array[m] + "\t" );                  }                  System.out.println();              }          }      }          public static void main(String[] args) {          ShellSort shellSort = new ShellSort();          int [] array = { 5 , 69 , 12 , 3 , 56 , 789 , 2 , 5648 , 23 };          shellSort.shellSort(array, array.length); // 注意为数组的个数          for ( int m = 0 ; m <= array.length - 1 ; m++) {              System.out.print(array[m] + "\t" );          }      } }

5. [代码]快速排序     

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 public class QuickSort {      public int partition( int [] sortArray, int low, int height) {          int key = sortArray[low]; // 刚开始以第一个数为标志数据          while (low < height) {              while (low < height && sortArray[height] >= key)                  height--; // 从后面开始找,找到比key值小的数为止              sortArray[low] = sortArray[height]; // 将该数放到key值的左边              while (low < height && sortArray[low] <= key)                  low++; // 从前面开始找,找到比key值大的数为止              sortArray[height] = sortArray[low]; // 将该数放到key值的右边          }          sortArray[low] = key; // 把key值填充到low位置,下次重新找key值          // 打印每次排序结果          for ( int i = 0 ; i <= sortArray.length - 1 ; i++) {              System.out.print(sortArray[i] + "\t" );          }          System.out.println();          return low;      }          public void sort( int [] sortArray, int low, int height) {          if (low < height) {              int result = partition(sortArray, low, height);              sort(sortArray, low, result - 1 );              sort(sortArray, result + 1 , height);          }      }          public static void main(String[] args) {          QuickSort quickSort = new QuickSort();          int [] array = { 5 , 69 , 12 , 3 , 56 , 789 , 2 , 5648 , 23 };          for ( int i = 0 ; i <= array.length - 1 ; i++) {              System.out.print(array[i] + "\t" );          }          System.out.println();          quickSort.sort(array, 0 , 8 );          for ( int i = 0 ; i <= array.length - 1 ; i++) {              System.out.print(array[i] + "\t" );          }      } }
    原文作者:五大常用算法
    原文地址: https://blog.csdn.net/u010525970/article/details/46581115
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
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