使用二进制搜索查找目标数的索引

Question

这是我第一次使用这个平台提问。我想知道以下代码有什么问题，它们没有在主代码末尾打印出目标数字的索引。发生了什么？祝那些阅读本文的人度过愉快的一天。

public class binarySearch {
    public static void main(String[] args) {
        Scanner keyboard=new Scanner(System.in);
        int target,index;
        int [] numArray={1,4,6,7,8,10,14,16,17,26,30,35,38,41};

        System.out.print("What do you want to find?");
        target=keyboard.nextInt();
        index=binarySearch(numArray, target);
        System.out.println("The element is found at index:"+index);
    }

    static int binarySearch(int [] numArray, int target){
        int left=0;
        int right=numArray.length-1;
        int mid=(left+right)/2;
        while(left<=right){
            if(numArray[mid]==target){
                return mid;
            }else if(target<numArray[mid]){
                right=mid-1;
            }else{
                left=mid+1;
            }
        }
        return -1;
    }
}

Answer 1

您没有在循环内重新计算mid：

static int binarySearch(int [] numArray, int target){
    int left=0;
    int right=numArray.length-1;
    int mid=(left+right)/2;
    while(left<=right){
        mid=(left+right)/2;
        if(numArray[mid]==target){
            return mid;
        }else if(target<numArray[mid]){
            right=mid-1;
        }else{
            left=mid+1;
        }
    }
    return -1;
}