Java 选择、冒泡排序、折半查找(实例讲解)

//选择排序对数据进行升序排序
  public static void selectSortArray(int[] arr){
   for(int i = 0; i<arr.length-1;i++){
    for(int j = i+1;j<arr.length;j++){
     if(arr[i]>arr[j]){
      int temp = arr[j];
      arr[j] = arr[i];
      arr[i] = temp;
      }
    }
   }
  }

//冒泡排序对数据进行升序排序
 public static void bubbleSortArray(double[] arr){
  for(int i = 0;i<arr.length-1;i++){
   for(int j = 0;j<arr.length-1-i;j++){
    if(arr[j]>arr[j+1]){
     double temp = arr[j+1];
     arr[j+1] = arr[j];
     arr[j] = temp;
     }
   }
  }
 }

public static int binarySearch(int[] arr,int key){
  int max,min,mid;
  max = arr.length-1;
  min = 0;
  while(min<=max){
   mid = (max+min)/2;
   if(key>arr[mid]){
    min = mid+1;
   }else if (key<arr[mid]) {
    max = mid-1;
   }else{
    return mid;
   }
  }
  return -1;
 }