• 题目连接：35. 搜索插入位置

1- 思路

二分

• 二分左区间的三种情况。
• 由于目标值不一定在数组中，因此二分的过程中有三种情况判断

2- 实现

⭐35. 搜索插入位置——题解思路

class Solution {
    public int searchInsert(int[] nums, int target) {
        int left = 0;
        int right = nums.length-1;
        while(left<=right){
            int mid = left + (right-left)/2;
            if(nums[mid]<target){
                left = mid+1;
            }else if(nums[mid] > target){
                right = mid-1;
            }else{
                return mid;
            }
        }
        return left;
    }
}

3- ACM 实现

public class searchIndex {




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

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String input = sc.nextLine();
        input = input.substring(1,input.length()-1);
        String[] parts = input.split(",");
        int[] nums = new int[parts.length];
        for(int i = 0 ; i < parts.length;i++){
            nums[i] = Integer.parseInt(parts[i]);
        }
        System.out.println("输入target值");
        int target = sc.nextInt();
        System.out.println("结果是"+search(nums,target));
    }
}