35. Search Insert Position

二分查找，结束时left恰好停在比目标值大的index上，right恰好停在比目标值小的index上

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