java中的排序算法

来源：互联网发布：扬州大学怎么样知乎编辑：程序博客网时间：2024/05/18 17:04

public class SortDemo {
private int [] ar;
public static final int defaultSize = 10;
public SortDemo(int length){
  ar = new int[length];
  init();
}
public SortDemo(){
  this(defaultSize);
}
public SortDemo(int [] a){
  ar = a;
}
//随机给数组元素赋值
public void init(){
  for(int i = 0;i<ar.length;i++){
   System.out.println((int)Math.random());
  }
}
//把数组输出到屏幕
public void showSort() {
  for(int i = 0;i<ar.length;i++){
   System.out.print(ar[i]+" ");
  }
}

//1、冒泡排序
public void bubbleSort() {
  int temp;
  for (int i=0;i<ar.length-1;i++) {

   for (int j =0;j<ar.length-i;j++) {

    if(ar[j]>ar[j+1]) {
     temp = ar[j];
     ar[j] = ar[j+1];
     ar[j+1] = temp;
    }
   }
  }
}

//2、选择排序

public void selectSort() {

int temp;

for(int i = 0;i<ar.length-1;i++) {

for(int j = i+1;j<ar.length;j++) {

if(ar[i]>ar[j]) {

temp = ar[i];

ar[j] = temp;

ar[i] = ar[j];

}

}
public static void main(String [] args) {
  int [] ts = {21,32,43,45,52,56,67,24,57,85,3};
  SortDemo s1 = new SortDemo(ts);
  System.out.println("数组未排序前：");
  s1.showSort();
  System.out.println();
  s1.bubbleSort();
  System.out.println("数组排序后：");
  s1.showSort();
}
}