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.

Here are few examples.

[1,3,5,6], 5 → 2

[1,3,5,6], 2 → 1

[1,3,5,6], 7 → 4

[1,3,5,6], 0 → 0

use binary search to find the interval where target located.

public int searchInsert(int[] A, int target) {
        if (A==null||A.length==0) {
            return -1;
        }

        int left = 0;
        int right = A.length-1;
        int middle = 0;

        while(left<=right) {
            middle = left+(right-left)/2;
            if (A[middle]==target) {
                return middle;
            } else if (A[middle]<target) {
                if (right==middle) {
                    return right+1;
                }

                left = middle + 1;
            } else {
                if (left==middle) {
                    return left;
                }
                right = middle-1;
            }
        }

        return middle;
    }