LeetCode-35.Search Insert Position

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

You may assume no duplicates in the array.

Example 1:

Input: [1,3,5,6], 5
Output: 2

Example 2:

Input: [1,3,5,6], 2
Output: 1

Example 3:

Input: [1,3,5,6], 7
Output: 4

Example 4:

Input: [1,3,5,6], 0
Output: 0 

binary search finds the first element greater than or equal to a given value, i.e. the insertion position, the time complexity of O (logn)

    public int searchInsert(int[] nums, int target) {
        if(null == nums || 0== nums.length){
            return -1;
        }
        int left =0;
        int right =nums.length-1;
        while(left<=right){
            int mid = left+((right-left)>>1);
            if(nums[mid]<target){
                left = mid+1;
            }
            the else  IF (MID == 0 || the nums [-MID. 1] <target) { // plurality is greater than a first value equal to the target 
                return MID;
            }
            else{
                right = mid-1;
            }
        }
        return nums.length;
    }