解题思路：

二分法模板

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) >> 1);
            if (nums[mid] == target)
                return mid;
            else if (nums[mid] < target)
                left = mid + 1;
            else
                right = mid - 1;
        }
        return left;
    }
}