35.搜索插入位置 (Easy)*

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