package day04.d1.shuzu;
import java.util.Arrays;
/**
* 数组算法测试
* 冒泡排序
* 快速选择排序
* ...
* @author Administrator
*
*/
public class ArrayArithmeticTest {
public static void main(String[] args) {
// TODO Auto-generated method stub
int[] arr={50,40,30,35};
selectSort(arr);
System.out.println(Arrays.toString(arr));
int[] arr2={50,40,30,35};
bubbleSort(arr2);
System.out.println(Arrays.toString(arr2));
int[] arr3={30,2,5,3,7,1,6,4,12,56,45,33};
Arrays.sort(arr3);
int index=binarySearch(arr3,0,arr3.length,7);
System.out.println("index "+index);
}
/**
* 选择排序
* @param arr
*/
public static void selectSort(int[] arr){
int temp=0;
for (int i = 0; i < arr.length-1; i++) {
for (int j = i+1; j < arr.length; j++) {
if(arr[i]>arr[j]){
temp=arr[i];
arr[i]=arr[j];
arr[j]=temp;
}
}
}
}
/**
* 冒泡排序
* @param arr
*/
public static void bubbleSort(int[] arr){
int temp=0;
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]){
temp=arr[j];
arr[j]=arr[j+1];
arr[j+1]=temp;
}
}
}
}
/**
* 二分查找
* @param arr
* @param start
* @param end
* @param key
*/
public static int binarySearch(int[] arr,int start,int end,int key){
int mid=(start+end)/2;
if(arr[mid]==key){
return mid;
}else if(arr[mid]>key){
end=mid;
binarySearch(arr,start,end,key);
}else if(arr[mid]<key){
start=mid;
binarySearch(arr,start,end,key);
}
return 0;
}
}