数据结构排序问题---选择---希尔---归并

/**
 * 
 */
package com;

/**
 * @author wenb
 * @time 下午01:41:21
 * @date 2014-10-24
 */
public class SelectSort {
    
    public static void main(String[] args){
        
        int[] a = {1,3,2,21,5,12,98,54};
        Select(a);
        for(int i=0;i<a.length;i++){
        System.out.print(a[i]+" ");        
        }
    }

    /**
     * @param a
     */
    private static void Select(int[] a) {
        // TODO Auto-generated method stub

        int temp;
        for(int i=0;i<a.length;i++){ //控制整体趟数
            
            int k = i;
            //找最小的
            for(int j =a.length-1;j>i;j--){
                if(a[j]<a[k]){
                    k = j;
                }
            }
            
            temp = a[i];
            a[i] = a[k];
            a[k] = temp;
        }
    }
}

/**
 * 
 */
package com;

/**
 * @author wenb
 * @time 下午02:44:18
 * @date 2014-10-24
 */
    public class ShellSort {  
      
        public static void main(String[] args) {  
      
            int[] a = {1,3,2,21,5,12,98,54};
            shellSort(a);
            for (int i = 0; i < a.length; i++) {  
                System.out.print(a[i] + " ");  
            }    
      
        }  
      
        public static void shellSort(int[] data) {  
            
            // 计算出最大的h值  
            int h = 1;  
            while (h <= data.length / 3) {  
                h = h * 3 + 1;  
            }  
            
            while (h > 0) {  
                for (int i = h; i < data.length; i += h) {  
                    if (data[i] < data[i - h]) {  
                        int tmp = data[i];  
                        int j = i - h;  
                        while (j >= 0 && data[j] > tmp) {  
                            data[j + h] = data[j];  
                            j -= h;  
                        }  
                        data[j + h] = tmp;   
                    }  
                }  

                h = (h - 1) / 3;        // 计算出下一个h值  
            }  
        }  
        
    }  

/**
 * 
 */
package com;

import java.util.Arrays;

/**
 * @author wenb
 * @time 下午03:41:12
 * @date 2014-10-24
 */
public class MergeSort {


    public static void main(String[] args) {  
  
         int[] a = {1,3,2,21,5,12,98,54};
        MergeSort.sort(a, 0, a.length-1);  
        for (int i = 0; i < a.length; i++) {  
            System.out.print(a[i] + " ");  
        }  
    }
    
    public static int[] sort(int[] nums, int low, int high) {  
        int mid = (low + high) / 2;  
        if (low < high) {  
            // 左边  
            sort(nums, low, mid);  
            // 右边  
            sort(nums, mid + 1, high);  
            // 左右归并  
            merge(nums, low, mid, high);  
        }  
        return nums;  
    }  
  
    public static void merge(int[] nums, int low, int mid, int high) {  
        int[] temp = new int[high - low + 1];  
        int i = low;// 左指针  
        int j = mid + 1;// 右指针  
        int k = 0;  
  
        // 把较小的数先移到新数组中  
        while (i <= mid && j <= high) {  
            if (nums[i] < nums[j]) {  
                temp[k++] = nums[i++];  
            } else {  
                temp[k++] = nums[j++];  
            }  
        }  
  
        // 把左边剩余的数移入数组  
        while (i <= mid) {  
            temp[k++] = nums[i++];  
        }  
  
        // 把右边边剩余的数移入数组  
        while (j <= high) {  
            temp[k++] = nums[j++];  
        }  
  
        // 把新数组中的数覆盖nums数组  
        for (int k2 = 0; k2 < temp.length; k2++) {  
            nums[k2 + low] = temp[k2];  
        }  
    }  
    
}