Given a n x n matrix. The problem is to sort the matrix row-wise and column wise.
Examples:
Input : mat[][] = { {4, 1, 3}, {9, 6, 8}, {5, 2, 7} } Output : 1 3 4 2 5 7 6 8 9 Input : mat[][] = { {12, 7, 1, 8}, {20, 9, 11, 2}, {15, 4, 5, 13}, {3, 18, 10, 6} } Output : 1 5 8 12 2 6 10 15 3 7 11 18 4 9 13 20
Approach: Following are the steps:
- Sort each row of the matrix.
- Get transpose of the matrix.
- Again sort each row of the matrix.
- Again get transpose of the matrix.
Algorithm for getting transpose of the matrix:
for (int i = 0; i PHP
<?php
// PHP implementation to sort
// the matrix row-wise and
// column-wise
$MAX_SIZE
= 10;
// function to sort each
// row of the matrix
function
sortByRow(&
$mat
,
$n
)
{
for
(
$i
= 0;
$i
<
$n
;
$i
++)
// sorting row number 'i'
sort(
$mat
[
$i
]);
}
// function to find
// transpose of the matrix
function
transpose(&
$mat
,
$n
)
{
for
(
$i
= 0;
$i
<
$n
;
$i
++)
{
for
(
$j
=
$i
+ 1;
$j
<
$n
;
$j
++)
{
// swapping element at index (i, j)
// by element at index (j, i)
$t
=
$mat
[
$i
][
$j
];
$mat
[
$i
][
$j
] =
$mat
[
$j
][
$i
];
$mat
[
$j
][
$i
] =
$t
;
}
}
}
// function to sort
// the matrix row-wise
// and column-wise
function
sortMatRowAndColWise(&
$mat
,
$n
)
{
// sort rows of mat[][]
sortByRow(
$mat
,
$n
);
// get transpose of mat[][]
transpose(
$mat
,
$n
);
// again sort rows of mat[][]
sortByRow(
$mat
,
$n
);
// again get transpose of mat[][]
transpose(
$mat
,
$n
);
}
// function to print the matrix
function
printMat(&
$mat
,
$n
)
{
for
(
$i
= 0;
$i
<
$n
;
$i
++)
{
for
(
$j
= 0;
$j
<
$n
;
$j
++)
echo
$mat
[
$i
][
$j
] .
" "
;
echo
"
";
}
}
// Driver Code
$mat
=
array
(
array
( 4, 1, 3 ),
array
( 9, 6, 8 ),
array
( 5, 2, 7 ));
$n
= 3;
echo
"Original Matrix:
";
printMat(
$mat
,
$n
);
sortMatRowAndColWise(
$mat
,
$n
);
echo
"
Matrix After Sorting:
";
printMat(
$mat
,
$n
);
// This code is contributed
// by ChitraNayal
?>
Output:
Original Matrix: 4 1 3 9 6 8 5 2 7 Matrix After Sorting: 1 3 4 2 5 7 6 8 9Time Complexity: O(n2log2n).
Auxiliary Space: O(1).
Please refer complete article on Sort the matrix row-wise and column-wise for more details!
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