Create a min heap of elements from first row of 2D array
harr = [ 0 ] * n NEW_LINE for i in range ( n ) : NEW_LINE INDENT harr [ i ] = HeapNode ( mat [ 0 ] [ i ] , 0 , i ) NEW_LINE DEDENT buildHeap ( harr , n ) NEW_LINE hr = HeapNode ( 0 , 0 , 0 ) NEW_LINE for i in range ( k ) : NEW_LINE