java实现各种排序算法

java实现各种排序算法

 import java.util.Arrays;

 public class SomeSort {

     public static void main(String[] args) {
         // TODO Auto-generated method stub

         int[] a = { 1, 5, 6, 2, 7, 4, 9 };// 升序
         // selectionSort(a);
         //bubbleSort(a);
         insertSort(a);
         System.out.println(Arrays.toString(a));
     }

     // 选择排序
     public static void selectionSort(int[] a) {

         for (int i = 0; i < a.length; i++) {
             int min = a[i], temp;
             for (int j = i; j < a.length; j++) {
                 if (min > a[j]) {
                     temp = min;
                     min = a[j];
                     a[j] = temp;
                 }
             }
             a[i] = min;
         }
     }

     // 冒泡排序
     public static void bubbleSort(int[] a) {
         int temp;
         for (int i = 0; i < a.length; i++) {

             for (int j = 0; j < a.length - i - 1; j++) {
                 if (a[j] > a[j + 1]) {
                     temp = a[j];
                     a[j] = a[j + 1];
                     a[j + 1] = temp;
                 }
             }
         }
     }

     //插入排序
     public static void insertSort(int[] a){
         int temp;
         for(int i = 1;i < a.length;i ++){
             for(int j = i;j > 0;j --){
                 if(a[j] < a[j - 1]){
                     temp = a[j];
                     a[j] = a[j - 1];
                     a[j - 1] = temp;
                 }
             }
         }
     }

 }