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# Print a given matrix in reverse spiral form

• Difficulty Level : Medium
• Last Updated : 21 Apr, 2021

Given a 2D array, print it in reverse spiral form. We have already discussed Print a given matrix in spiral form. This article discusses how to do the reverse printing. See the following examples.

```Input:
1    2   3   4
5    6   7   8
9   10  11  12
13  14  15  16
Output:
10 11 7 6 5 9 13 14 15 16 12 8 4 3 2 1
Input:
1   2   3   4  5   6
7   8   9  10  11  12
13  14  15 16  17  18
Output:
11 10 9 8 7 13 14 15 16 17 18 12 6 5 4 3 2 1```

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## C++

 `// This is a modified code of``// https://www.geeksforgeeks.org/print-a-given-matrix-in-spiral-form/``#include ``#define R 3``#define C 6``using` `namespace` `std;` `// Function that print matrix in reverse spiral form.``void` `ReversespiralPrint(``int` `m, ``int` `n, ``int` `a[R][C])``{``    ``// Large array to initialize it``    ``// with elements of matrix``    ``long` `int` `b;``    ` `    ``/* k - starting row index``    ``l - starting column index*/``    ``int` `i, k = 0, l = 0;``    ` `    ``// Counter for single dimension array``    ``//in which elements will be stored``    ``int` `z = 0;``    ` `    ``// Total elements in matrix``    ``int` `size = m*n;` `    ``while` `(k < m && l < n)``    ``{``        ``// Variable to store value of matrix.``        ``int` `val;``        ` `        ``/* Print the first row from the remaining rows */``        ``for` `(i = l; i < n; ++i)``        ``{``            ``// printf("%d ", a[k][i]);``            ``val = a[k][i];``            ``b[z] = val;``            ``++z;``        ``}``        ``k++;` `        ``/* Print the last column from the remaining columns */``        ``for` `(i = k; i < m; ++i)``        ``{``            ``// printf("%d ", a[i][n-1]);``            ``val = a[i][n-1];``            ``b[z] = val;``            ``++z;``        ``}``        ``n--;` `        ``/* Print the last row from the remaining rows */``        ``if` `( k < m)``        ``{``            ``for` `(i = n-1; i >= l; --i)``            ``{``                ``// printf("%d ", a[m-1][i]);``                ``val = a[m-1][i];``                ``b[z] = val;``                ``++z;``            ``}``            ``m--;``        ``}` `        ``/* Print the first column from the remaining columns */``        ``if` `(l < n)``        ``{``            ``for` `(i = m-1; i >= k; --i)``            ``{``                ``// printf("%d ", a[i][l]);``                ``val = a[i][l];``                ``b[z] = val;``                ``++z;``            ``}``            ``l++;``        ``}``    ``}``    ``for` `(``int` `i=size-1 ; i>=0 ; --i)``    ``{``        ``cout<

## Java

 `// JAVA Code for Print a given matrix in``// reverse spiral form``class` `GFG {` `    ``public` `static` `int` `R = ``3``, C = ``6``;``    ` `    ``// Function that print matrix in reverse spiral form.``    ``public` `static` `void` `ReversespiralPrint(``int` `m, ``int` `n,``                                             ``int` `a[][])``    ``{``        ``// Large array to initialize it``        ``// with elements of matrix``        ``long` `b[] = ``new` `long``[``100``];``         ` `        ``/* k - starting row index``        ``l - starting column index*/``        ``int` `i, k = ``0``, l = ``0``;``         ` `        ``// Counter for single dimension array``        ``//in which elements will be stored``        ``int` `z = ``0``;``         ` `        ``// Total elements in matrix``        ``int` `size = m * n;``     ` `        ``while` `(k < m && l < n)``        ``{``            ``// Variable to store value of matrix.``            ``int` `val;``             ` `            ``/* Print the first row from the remaining``            ``rows */``            ``for` `(i = l; i < n; ++i)``            ``{``                ` `                ``val = a[k][i];``                ``b[z] = val;``                ``++z;``            ``}``            ``k++;``     ` `            ``/* Print the last column from the remaining``            ``columns */``            ``for` `(i = k; i < m; ++i)``            ``{``                ` `                ``val = a[i][n-``1``];``                ``b[z] = val;``                ``++z;``            ``}``            ``n--;``     ` `            ``/* Print the last row from the remaining``            ``rows */``            ``if` `( k < m)``            ``{``                ``for` `(i = n-``1``; i >= l; --i)``                ``{``                    ` `                    ``val = a[m-``1``][i];``                    ``b[z] = val;``                    ``++z;``                ``}``                ``m--;``            ``}``     ` `            ``/* Print the first column from the remaining``            ``columns */``            ``if` `(l < n)``            ``{``                ``for` `(i = m-``1``; i >= k; --i)``                ``{``                    ` `                    ``val = a[i][l];``                    ``b[z] = val;``                    ``++z;``                ``}``                ``l++;``            ``}``        ``}``        ` `        ``for` `(``int` `x = size-``1` `; x>=``0` `; --x)``        ``{``            ``System.out.print(b[x]+``" "``);``        ``}``    ``}   ``    ` `    ``/* Driver program to test above function */``    ``public` `static` `void` `main(String[] args)``    ``{``        ``int` `a[][] = { {``1``, ``2``, ``3``, ``4``, ``5``, ``6``},``                    ``{``7``, ``8``, ``9``, ``10``, ``11``, ``12``},``                    ``{``13``, ``14``, ``15``, ``16``, ``17``, ``18``}};``        ` `        ``ReversespiralPrint(R, C, a);``       ` `    ``}``  ``}``// This code is contributed by Arnav Kr. Mandal.`

## Python3

 `# Python3 Code to Print a given ``# matrix in reverse spiral form` `# This is a modified code of``# https:#www.geeksforgeeks.org/print-a-given-matrix-in-spiral-form/``R, C ``=` `3``, ``6` `def` `ReversespiralPrint(m, n, a):` `    ``# Large array to initialize it``    ``# with elements of matrix``    ``b ``=` `[``0` `for` `i ``in` `range``(``100``)]` `    ``#/* k - starting row index``    ``#l - starting column index*/``    ``i, k, l ``=` `0``, ``0``, ``0` `    ``# Counter for single dimension array``    ``# in which elements will be stored``    ``z ``=` `0` `    ``# Total elements in matrix``    ``size ``=` `m ``*` `n` `    ``while` `(k < m ``and` `l < n):``        ` `        ``# Variable to store value of matrix.``        ``val ``=` `0` `        ``# Print the first row``        ``# from the remaining rows``        ``for` `i ``in` `range``(l, n):``            ` `            ``# printf("%d ", a[k][i])``            ``val ``=` `a[k][i]``            ``b[z] ``=` `val``            ``z ``+``=` `1``        ``k ``+``=` `1` `        ``# Print the last column``        ``# from the remaining columns``        ``for` `i ``in` `range``(k, m):` `            ``# printf("%d ", a[i][n-1])``            ``val ``=` `a[i][n ``-` `1``]``            ``b[z] ``=` `val``            ``z ``+``=` `1` `        ``n ``-``=` `1` `        ``# Print the last row``        ``# from the remaining rows``        ``if` `(k < m):``            ``for` `i ``in` `range``(n ``-` `1``, l ``-` `1``, ``-``1``):``                ` `                ``# printf("%d ", a[m-1][i])``                ``val ``=` `a[m ``-` `1``][i]``                ``b[z] ``=` `val``                ``z ``+``=` `1` `        ``m ``-``=` `1` `        ``# Print the first column``        ``# from the remaining columns``        ``if` `(l < n):``            ``for` `i ``in` `range``(m ``-` `1``, k ``-` `1``, ``-``1``):``                ` `                ``# printf("%d ", a[i][l])``                ``val ``=` `a[i][l]``                ``b[z] ``=` `val``                ``z ``+``=` `1``            ``l ``+``=` `1` `    ``for` `i ``in` `range``(size ``-` `1``, ``-``1``, ``-``1``):``        ``print``(b[i], end ``=` `" "``)` `# Driver Code``a ``=` `[[``1``, ``2``, ``3``, ``4``, ``5``, ``6``],``     ``[``7``, ``8``, ``9``, ``10``, ``11``, ``12``],``     ``[``13``, ``14``, ``15``, ``16``, ``17``, ``18``]]` `ReversespiralPrint(R, C, a)` `# This code is contributed by mohit kumar`

## C#

 `// C# Code for Print a given matrix in``// reverse spiral form``using` `System;``class` `GFG {` `    ``public` `static` `int` `R = 3, C = 6;``    ` `    ``// Function that print matrix in reverse spiral form.``    ``public` `static` `void` `ReversespiralPrint(``int` `m, ``int` `n,``                                            ``int` `[,]a)``    ``{``        ``// Large array to initialize it``        ``// with elements of matrix``        ``long` `[]b = ``new` `long``;``        ` `        ``/* k - starting row index``        ``l - starting column index*/``        ``int` `i, k = 0, l = 0;``        ` `        ``// Counter for single dimension array``        ``//in which elements will be stored``        ``int` `z = 0;``        ` `        ``// Total elements in matrix``        ``int` `size = m * n;``    ` `        ``while` `(k < m && l < n)``        ``{``            ``// Variable to store value of matrix.``            ``int` `val;``            ` `            ``/* Print the first row from the remaining``            ``rows */``            ``for` `(i = l; i < n; ++i)``            ``{``                ` `                ``val = a[k,i];``                ``b[z] = val;``                ``++z;``            ``}``            ``k++;``    ` `            ``/* Print the last column from the remaining``            ``columns */``            ``for` `(i = k; i < m; ++i)``            ``{``                ` `                ``val = a[i,n-1];``                ``b[z] = val;``                ``++z;``            ``}``            ``n--;``    ` `            ``/* Print the last row from the remaining``            ``rows */``            ``if` `( k < m)``            ``{``                ``for` `(i = n-1; i >= l; --i)``                ``{``                    ` `                    ``val = a[m-1,i];``                    ``b[z] = val;``                    ``++z;``                ``}``                ``m--;``            ``}``    ` `            ``/* Print the first column from the remaining``            ``columns */``            ``if` `(l < n)``            ``{``                ``for` `(i = m-1; i >= k; --i)``                ``{``                    ` `                    ``val = a[i,l];``                    ``b[z] = val;``                    ``++z;``                ``}``                ``l++;``            ``}``        ``}``        ` `        ``for` `(``int` `x = size-1 ; x>=0 ; --x)``        ``{``        ``Console.Write(b[x]+``" "``);``        ``}``    ``}``    ` `    ``/* Driver program to test above function */``    ``public` `static` `void` `Main()``    ``{``        ``int` `[ ,]a = { {1, 2, 3, 4, 5, 6},``                    ``{7, 8, 9, 10, 11, 12},``                    ``{13, 14, 15, 16, 17, 18}};``        ` `        ``ReversespiralPrint(R, C, a);``        ` `    ``}``}``// This code is contributed by vt_m.`

## PHP

 `= ``\$l``; --``\$i``)``            ``{``                ` `                ``// printf("%d ", a[m-1][i]);``                ``\$val` `= ``\$a``[``\$m``-1][``\$i``];``                ``\$b``[``\$z``] = ``\$val``;``                ``++``\$z``;``            ``}``            ``\$m``--;``        ``}` `        ``// Print the first column``        ``// from the remaining columns``        ``if` `(``\$l` `< ``\$n``)``        ``{``            ``for` `(``\$i` `= ``\$m` `- 1; ``\$i` `>= ``\$k``; --``\$i``)``            ``{``                ``\$val` `= ``\$a``[``\$i``][``\$l``];``                ``\$b``[``\$z``] = ``\$val``;``                ``++``\$z``;``            ``}``            ``\$l``++;``        ``}``    ``}``    ``for` `(``\$i` `= ``\$size` `- 1; ``\$i` `>= 0; --``\$i``)``    ``{``        ``echo` `\$b``[``\$i``].``" "``;``    ``}``}` `    ``// Driver Code``    ``\$a``= ``array``(``array``(1, 2, 3, 4, 5, 6),``              ``array``(7, 8, 9, 10, 11, 12),``              ``array``(13, 14, 15, 16, 17, 18));``    ``ReversespiralPrint(``\$R``, ``\$C``, ``\$a``);` `// This Code is contributed by mits``?>`

## Javascript

 ``

Output:

`11 10 9 8 7 13 14 15 16 17 18 12 6 5 4 3 2 1`

This article is contributed by Sahil Rajput. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.