Given two values m and n, fill a matrix of size ‘m*n’ in a spiral (or circular) fashion (clockwise) with natural numbers from 1 to m*n.
Examples:
Input : m = 4, n = 4
Output : 1 2 3 4
12 13 14 5
11 16 15 6
10 9 8 7
Input : m = 3, n = 4
Output : 1 2 3 4
10 11 12 5
9 8 7 6
The idea is based on Print a given matrix in spiral form. We create a matrix of size m * n and traverse it in a spiral fashion. While traversing, we keep track of a variable “val” to fill the next value, we increment “val” one by one and put its values in the matrix.
Implementation:
C++
#include <bits/stdc++.h>
using namespace std;
const int MAX = 100;
void spiralFill(int m, int n, int a[][MAX])
{
int val = 1;
int k = 0, l = 0;
while (k < m && l < n)
{
for (int i = l; i < n; ++i)
a[k][i] = val++;
k++;
for (int i = k; i < m; ++i)
a[i][n-1] = val++;
n--;
if (k < m)
{
for (int i = n-1; i >= l; --i)
a[m-1][i] = val++;
m--;
}
if (l < n)
{
for (int i = m-1; i >= k; --i)
a[i][l] = val++;
l++;
}
}
}
int main()
{
int m = 4, n = 4;
int a[MAX][MAX];
spiralFill(m, n, a);
for (int i=0; i<m; i++)
{
for (int j=0; j<n; j++)
cout << a[i][j] << " ";
cout << endl;
}
return 0;
}
|
C
#include <stdio.h>
const int MAX = 100;
void spiralFill(int m, int n, int a[][MAX])
{
int val = 1;
int k = 0, l = 0;
while (k < m && l < n)
{
for (int i = l; i < n; ++i)
a[k][i] = val++;
k++;
for (int i = k; i < m; ++i)
a[i][n-1] = val++;
n--;
if (k < m)
{
for (int i = n-1; i >= l; --i)
a[m-1][i] = val++;
m--;
}
if (l < n)
{
for (int i = m-1; i >= k; --i)
a[i][l] = val++;
l++;
}
}
}
int main()
{
int m = 4, n = 4;
int a[MAX][MAX];
spiralFill(m, n, a);
for (int i=0; i<m; i++)
{
for (int j=0; j<n; j++)
printf("%d ",a[i][j]);
printf("\n");
}
return 0;
}
|
Java
import java.io.*;
class GFG {
static int MAX = 100;
static void spiralFill(int m, int n, int a[][]) {
int val = 1;
int k = 0, l = 0;
while (k < m && l < n) {
for (int i = l; i < n; ++i) {
a[k][i] = val++;
}
k++;
for (int i = k; i < m; ++i) {
a[i][n - 1] = val++;
}
n--;
if (k < m) {
for (int i = n - 1; i >= l; --i) {
a[m - 1][i] = val++;
}
m--;
}
if (l < n) {
for (int i = m - 1; i >= k; --i) {
a[i][l] = val++;
}
l++;
}
}
}
public static void main(String[] args) {
int m = 4, n = 4;
int a[][] = new int[MAX][MAX];
spiralFill(m, n, a);
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
System.out.print(a[i][j] + " ");
}
System.out.println("");
}
}
}
|
Python3
def spiralFill(m, n, a):
val = 1
k, l = 0, 0
while (k < m and l < n):
for i in range(l, n):
a[k][i] = val
val += 1
k += 1
for i in range(k, m):
a[i][n - 1] = val
val += 1
n -= 1
if (k < m):
for i in range(n - 1, l - 1, -1):
a[m - 1][i] = val
val += 1
m -= 1
if (l < n):
for i in range(m - 1, k - 1, -1):
a[i][l] = val
val += 1
l += 1
if __name__ == '__main__':
m, n = 4, 4
a = [[0 for j in range(n)] for i in range(m)]
spiralFill(m, n, a)
for i in range(m):
for j in range(n):
print(a[i][j], end=' ')
print('')
|
C#
using System;
class GFG {
static int MAX = 100;
static void spiralFill(int m, int n, int[,] a) {
int val = 1;
int k = 0, l = 0;
while (k < m && l < n) {
for (int i = l; i < n; ++i) {
a[k,i] = val++;
}
k++;
for (int i = k; i < m; ++i) {
a[i,n - 1] = val++;
}
n--;
if (k < m) {
for (int i = n - 1; i >= l; --i) {
a[m - 1,i] = val++;
}
m--;
}
if (l < n) {
for (int i = m - 1; i >= k; --i) {
a[i,l] = val++;
}
l++;
}
}
}
public static void Main() {
int m = 4, n = 4;
int[,] a = new int[MAX,MAX];
spiralFill(m, n, a);
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
Console.Write(a[i,j] + " ");
}
Console.Write("\n");
}
}
}
|
PHP
<?php
function spiralFill($m, $n, &$a)
{
$val = 1;
$k = 0;
$l = 0;
while ($k < $m && $l < $n)
{
for ($i = $l; $i < $n; ++$i)
$a[$k][$i] = $val++;
$k++;
for ($i = $k; $i < $m; ++$i)
$a[$i][$n - 1] = $val++;
$n--;
if ($k < $m)
{
for ($i = $n - 1; $i >= $l; --$i)
$a[$m - 1][$i] = $val++;
$m--;
}
if ($l < $n)
{
for ($i = $m - 1; $i >= $k; --$i)
$a[$i][$l] = $val++;
$l++;
}
}
}
$m = 4;
$n = 4;
spiralFill($m, $n, $a);
for ($i = 0; $i < $m; $i++)
{
for ($j = 0; $j < $n; $j++)
{
echo ($a[$i][$j]);
echo (" ");
}
echo ("\n");
}
?>
|
Javascript
<script>
const MAX = 100;
function spiralFill(m, n, a)
{
let val = 1;
let k = 0, l = 0;
while (k < m && l < n)
{
for (let i = l; i < n; ++i)
a[k][i] = val++;
k++;
for (let i = k; i < m; ++i)
a[i][n-1] = val++;
n--;
if (k < m)
{
for (let i = n - 1; i >= l; --i)
a[m-1][i] = val++;
m--;
}
if (l < n)
{
for (let i = m - 1; i >= k; --i)
a[i][l] = val++;
l++;
}
}
}
let m = 4, n = 4;
let a = Array.from(Array(MAX), () => new Array(MAX));
spiralFill(m, n, a);
for (let i = 0; i < m; i++)
{
for (let j = 0; j < n; j++)
document.write(a[i][j] + " ");
document.write("<br>");
}
</script>
|
Output
1 2 3 4
12 13 14 5
11 16 15 6
10 9 8 7
Time Complexity: O(m * n)
Space Complexity: O(m * n)
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Last Updated :
12 Dec, 2022
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