74. Search a 2D Matrix

class Solution {
public:
    bool searchMatrix(vector<vector<int>>& matrix, int target) 
    {
        int row = 0;

        for(int i=0; i<matrix.size(); i++)
        {
            if(matrix[i][0] <= target && target <= matrix[i][matrix[i].size()-1])
            {
                row = i;
                break;
            }
        }
        int s = 0, e = matrix[row].size()-1;
        int mid = s + (e - s)/2;

        while(s<=e)
        {
            if(matrix[row][mid]==target)
                return true;
            else if(matrix[row][mid]>target)
                e = mid -1;
            else
                s = mid + 1;
            
            mid = s + (e - s)/2;
        }

        return false;
        
    }
};