Search_in_a_2D_Matrix.cpp

bool searchMatrix(vector<vector<int>> &matrix, int x)
{

    int n = matrix.size();
    int m = matrix[0].size();
    int low = 0;
    int high = n * m - 1;
    int mid = (low + high) / 2;
    while (low <= high)
    {
        mid = (low + high) / 2;
        if (matrix[mid / m][mid % m] < x)
            low = mid + 1;
        else if (matrix[mid / m][mid % m] == x)
            return true;
        else
            high = mid - 1;
    }
    return false;
}