Search a 2D Matrix

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:

• Integers in each row are sorted from left to right.
• The first integer of each row is greater than the last integer of the previous row.

For example,

Consider the following matrix:

[
  [1,   3,  5,  7],
  [10, 11, 16, 20],
  [23, 30, 34, 50]
]

Given target = 3, return true.

class Solution {
public:
    bool searchMatrix(vector<vector<int>>& matrix, int target) {
        if(matrix.size() == 0){
            return false;
        }
        if(matrix[0].size() == 0){
            return false;
        }
        
        int rowNumber = 0;
        int colNumber = matrix[0].size()-1;
        
        while(rowNumber < matrix.size() && colNumber >= 0){
            
            if(matrix[rowNumber][colNumber] > target){
                colNumber--;
            }else if(matrix[rowNumber][colNumber] < target){
                rowNumber++;
            }else{
                return true;
            }
        }
        return false;
    }
};