java - 选择排序递归调用

Question

I was studying recursion problem I was going to call it, but it shows like this

import java.util.Arrays;


public class BinarySearch {
public static int binarySearch(int [] list, int key){
    int low = 0;
    int high = list.length -1;
    return binarySearch(list, key, low ,high);
}
public static int binarySearch(int [] list, int key, int low, int high){
    if(low > high){
        return (-low -1);}
    int mid = (low + high) / 2;
    if(key < list[mid])
        return binarySearch(list, key, low, mid - 1);
    else if(key == list[mid])
        return mid;
    else
        return binarySearch(list, key, mid + 1, high);
}
public static void main (String [] args){
    int [] list = {'1', '2','4','5'};
    binarySearch(list, 4);
    System.out.println(Arrays.toString(list));

}

}

output : [49, 50, 52, 53]

我应该怎样做才能使其正确？

Answer 1

您正在整数数组中存储字符:-

int [] list = {'1', '2','4','5'};

因此，您获得的值分别是 1, 2, 4, 5 的 ASCII 代码。因此，您的 binarySearch 方法将无法找到值 4。因为，它并不完全在那里。删除您的值周围的单引号。

其次，您没有打印 binarySearch 方法的返回值:-

binarySearch(list, 4);

应该是:-

System.out.println(binarySearch(list, 4));