Search a 2D Matrix

class Solution {public:    bool searchMatrix(vector<vector<int> > &matrix, int target) {        if(matrix.empty())  return false;        const size_t row=matrix.size();        const size_t column=matrix.front().size();        int left=0;        int right=row*column-1;        while(left<=right)        {            int mid=left+(right-left)/2;            if(matrix[mid/column][mid%column]==target)            {                return true;            }            else if(matrix[mid/column][mid%column]>target)            {                right=mid-1;            }            else            {                left=mid+1;            }        }        return false;    }};