【查找算法】之折半查找

import java.util.*;

public class Main {
static final int N=5;
public static void main(String[] args){

int[] shuzu = {2,8,14,25,36};

for(int k=0; k<N; k++){
System.out.println(shuzu[k]);
}
int index = BinarySearch(shuzu, N, 36);
System.out.println(index);
}

public static int BinarySearch(int arr[], int n, int target){
int low , mid, high;
low =0;
high = n-1;

while(low <= high){
mid = (low + high)/2; //找到中间位置元素的下标
if(arr[mid] == target){
return mid;//找到返回 下标
}else if(arr[mid] > target){
high = mid-1;//查找左半部分
}else if(arr[mid] < target){
low = mid +1; // 查找右半部分
}
}

return -1;
}
}