35.Search Insert Position

其實就是如果不是target, 找大於他的第一個index

class Solution {
  public:
    int searchInsert(vector<int> &nums, int target) {
        int l = 0;
        int r = nums.size() - 1;
        while (l <= r) {
            int mid = (r + l) / 2;
            if (nums[mid] == target) {
                return mid;
            } else if (nums[mid] < target) {
                l = mid + 1;
            } else {
                r = mid - 1;
            }
        }
        return l;
    }
};