How to Sort a Multidimensional Array by Value (original) (raw)
How to Sort a Multi-dimensional Array by Value
Last Updated : 11 Oct, 2023
What is Sorting?
Arranging data in an increasing or decreasing fashion according to their values is called **Sorting.
Below are shown some processes for sorting arrays of several dimensions.
Sorting a 1-Dimensional array:
We can sort any Dimensional array using the **sort method in C++.
**Syntax:
**sort(arr, arr+N)
Where,
- **arr, represents the name of the array.
- **arr + N, represents name of the array + size of the array
**Time Complexity: O(N * log N)
**Auxiliary Space: O(1)
**Example:-
C++ `
#include // for std::sort #include
const int SIZE = 5;
// A comparison function that sorts the array in ascending // order bool compare(int a, int b) { return a < b; }
int main() { // Initialize the array int arr[SIZE] = { 3, 5, 1, 2, 4 };
// Sort the array using the compare function
std::sort(arr, arr + SIZE, compare);
// Print the sorted array
for (int i = 0; i < SIZE; i++) {
std::cout << arr[i] << " ";
}
return 0;} // code by ksam24000
Java
// Java code for the approach
import java.util.Arrays; import java.util.Comparator;
public class GFG { // Driver code public static void main(String[] args) { final int SIZE = 5;
// Initialize the array
Integer[] arr = new Integer[SIZE];
arr[0] = 3;
arr[1] = 5;
arr[2] = 1;
arr[3] = 2;
arr[4] = 4;
// Sort the array using the compare function
Arrays.sort(arr, new Comparator<Integer>() {
@Override
public int compare(Integer a, Integer b) {
return a.compareTo(b);
}
});
// Print the sorted array
for (int i = 0; i < SIZE; i++) {
System.out.print(arr[i] + " ");
}
}}
Python3
from functools import cmp_to_key
def compare(a, b): return a - b
def main():
Initialize the list
arr = [3, 5, 1, 2, 4] # Sort the list using the compare function arr = sorted(arr, key=cmp_to_key(compare))
Print the sorted list
for i in arr: print(i, end=" ") main()
C#
using System; using System.Linq;
class GFG { static void Main(string[] args) { const int SIZE = 5;
// Initialize the array
int[] arr = { 3, 5, 1, 2, 4 };
// Sort the array using the compare function
Array.Sort(arr, (a, b) => a.CompareTo(b));
// Print the sorted array
foreach(int num in arr) {
Console.Write(num + " ");
}
}}
JavaScript
const SIZE = 5;
// A comparison function that sorts the array in ascending // order function compare(a, b) { return a - b; }
// Initialize the array let arr = [3, 5, 1, 2, 4];
// Sort the array using the compare function arr.sort(compare);
// Print the sorted array for (let i = 0; i < SIZE; i++) { console.log(arr[i] + " "); }
`
Sorting in Multi-Dimensional Array:
1. Sorting a 2 - Dimensional array Case:
**When you want to sort the row:
You can consider each row as a one-dimensional array and sort them individually
**Syntax:
for( int i=0; i<row; i++) {
**sort(arr[i], arr[i]+col)
}Where,
- **row : Total no of row
- **col : Total no of col
**Time Complexity: O(N * M * log M)
**Auxiliary Space: O(1)
**When you want to sort the entire matrix:
**Syntax:
**sort(&arr[0][0], &arr[r-1][col])
**Where
- **row: Total no of row
- **col: Total no of col
**Time Complexity: O(N*M log (N*M)) for sorting only and O(N*M) for printing the array
**Auxiliary Space: O(1)
Example:-
C++ `
// C++ code
#include <bits/stdc++.h> using namespace std; #define R 3 #define C 3
void sortfun(int arr[R][C]) { // One by one sort // individual rows. for (int i = 0; i < R; i++) sort(arr[i], arr[i] + C);
// Printing the sorted matrix
for (int i = 0; i < R; i++) {
for (int j = 0; j < C; j++)
cout << (arr[i][j]) << " ";
cout << endl;
}}
int main() { // Initialize the 2D array int arr[3][3] = { { 3, 2, 1 }, { 6, 5, 4 }, { 9, 8, 7 } };
// Sort the 2D array using the function
sortfun(arr);
return 0;} // code by ksam24000
Java
import java.util.Arrays;
public class Main { static final int R = 3; static final int C = 3;
static void sortfun(int arr[][]) {
// One by one sort
// individual rows.
for (int i = 0; i < R; i++) {
Arrays.sort(arr[i]);
}
// Printing the sorted matrix
for (int i = 0; i < R; i++) {
for (int j = 0; j < C; j++) {
System.out.print(arr[i][j] + " ");
}
System.out.println();
}}
public static void main(String[] args) { int arr[][] = { { 3, 2, 1 }, { 6, 5, 4 }, { 9, 8, 7 } };
// Sort the 2D array using the function
sortfun(arr);} }
Python3
Python3 code
R = 3 C = 3
def sortfun(arr): # One by one sort # individual rows. for i in range(R): arr[i].sort()
# Printing the sorted matrix
for i in range(R):
for j in range(C):
print(arr[i][j], end=" ")
print()Initialize the 2D array
arr = [ [ 3, 2, 1 ], [ 6, 5, 4 ], [ 9, 8, 7 ] ]
Sort the 2D array using the function
sortfun(arr)
C#
using System;
class Program { static int R = 3; static int C = 3;
static void SortMatrix(int[,] arr)
{
// One by one sort individual rows.
for (int i = 0; i < R; i++)
{
for (int j = 0; j < C - 1; j++)
{
for (int k = 0; k < C - j - 1; k++)
{
if (arr[i, k] > arr[i, k + 1])
{
// Swap elements if they are in the wrong order
int temp = arr[i, k];
arr[i, k] = arr[i, k + 1];
arr[i, k + 1] = temp;
}
}
}
}
// Printing the sorted matrix
for (int i = 0; i < R; i++)
{
for (int j = 0; j < C; j++)
{
Console.Write(arr[i, j] + " ");
}
Console.WriteLine();
}
}
static void Main()
{
// Initialize the 2D array
int[,] arr = { { 3, 2, 1 }, { 6, 5, 4 }, { 9, 8, 7 } };
// Sort the 2D array using the function
SortMatrix(arr);
}}
JavaScript
function sortfun(arr) { // One by one sort // individual rows. for (let i = 0; i < R; i++) arr[i].sort();
// Printing the sorted matrix
for (let i = 0; i < R; i++) {
for (let j = 0; j < C; j++)
console.log(arr[i][j] + " ");
console.log("\n");
}}
// Initialize the 2D array const R = 3; const C = 3; const arr = [[3, 2, 1], [6, 5, 4], [9, 8, 7]];
// Sort the 2D array using the function sortfun(arr);
`
**Note: This was for only 2-D array case but for any dimensional array it works the **same way.
2. Sorting for a 3-Dimensional Array:
Consider, the three dimensions to be X, Y and Z.
- So, for the first case, where we want to sort it according to the **row. The pseudocode will be:
for( int i=0; i<X; i++)
for(int j=0; j<Y; j++)
**sort(arr[i][j], arr[i][j]+Z)
**Time Complexity: O(X*Y*Z log Z)
**Auxiliary Space: O(1)
- Now, for the second case, where we want to sort entire matrix. The pseudocode will be:
sort(&arr[0][0][0], &arr[X-1][Y-1][Z])
**Time Complexity: O(X*Y*Z log (X*Y*Z))
**Auxiliary Space: O(1)
C++ `
#include <bits/stdc++.h> using namespace std;
const int R = 3, C = 3, H = 3;
void sortfun(int arr[][R][C]) { // One by one sort individual rows. for (int i = 0; i < H; i++) for (int j = 0; j < R; j++) sort(arr[i][j], arr[i][j] + C);
// Printing the sorted matrix
for (int i = 0; i < H; i++) {
cout << "Layer " << i + 1 << ":" << endl;
for (int j = 0; j < R; j++) {
for (int k = 0; k < C; k++)
cout << arr[i][j][k] << " ";
cout << endl;
}
}}
int main() { int arr[H][R][C] = { { { 3, 2, 1 }, { 6, 5, 4 }, { 9, 8, 7 } }, { { 11, 12, 13 }, { 14, 15, 16 }, { 17, 18, 19 } }, { { 21, 22, 23 }, { 24, 25, 26 }, { 27, 28, 29 } } };
sortfun(arr);
return 0;}
Java
import java.util.Arrays;
public class Main { static final int R = 3; static final int C = 3; static final int H = 3;
public static void sortfun(int[][][] arr)
{
// One by one sort individual rows.
for (int i = 0; i < H; i++)
for (int j = 0; j < R; j++)
Arrays.sort(arr[i][j]);
// Printing the sorted matrix
for (int i = 0; i < H; i++) {
System.out.println("Layer " + (i + 1) + ":");
for (int j = 0; j < R; j++) {
for (int k = 0; k < C; k++)
System.out.print(arr[i][j][k] + " ");
System.out.println();
}
}
}
public static void main(String[] args)
{
int[][][] arr
= { { { 3, 2, 1 }, { 6, 5, 4 }, { 9, 8, 7 } },
{ { 11, 12, 13 },
{ 14, 15, 16 },
{ 17, 18, 19 } },
{ { 21, 22, 23 },
{ 24, 25, 26 },
{ 27, 28, 29 } } };
sortfun(arr);
}}
Python3
R = 3 C = 3 H = 3
def sortfun(arr): # One by one sort individual rows. for i in range(H): for j in range(R): arr[i][j] = sorted(arr[i][j])
# Printing the sorted matrix
for i in range(H):
print("Layer " + str(i + 1) + ":")
for j in range(R):
for k in range(C):
print(arr[i][j][k], end=" ")
print()Initializing the 3D array
arr = [ [[3, 2, 1], [6, 5, 4], [9, 8, 7]], [[11, 12, 13], [14, 15, 16], [17, 18, 19]], [[21, 22, 23], [24, 25, 26], [27, 28, 29]] ]
sortfun(arr) #This code is contributed by Akash Jha
C#
using System;
public class Program { public static void Main() { int[,,] arr = new int[3, 3, 3] { { { 3, 2, 1 }, { 6, 5, 4 }, { 9, 8, 7 } }, { { 11, 12, 13 }, { 14, 15, 16 }, { 17, 18, 19 } }, { { 21, 22, 23 }, { 24, 25, 26 }, { 27, 28, 29 } } }; Console.WriteLine("Original array:"); PrintArray(arr);
int[] flatArr = new int[arr.Length];
int index = 0;
for (int i = 0; i < arr.GetLength(0); i++)
{
for (int j = 0; j < arr.GetLength(1); j++)
{
for (int k = 0; k < arr.GetLength(2); k++)
{
flatArr[index++] = arr[i, j, k];
}
}
}
Array.Sort(flatArr);
index = 0;
for (int i = 0; i < arr.GetLength(0); i++)
{
for (int j = 0; j < arr.GetLength(1); j++)
{
for (int k = 0; k < arr.GetLength(2); k++)
{
arr[i, j, k] = flatArr[index++];
}
}
}
Console.WriteLine("Sorted array:");
PrintArray(arr);
}
public static void PrintArray(int[,,] arr)
{
for (int i = 0; i < arr.GetLength(0); i++)
{
for (int j = 0; j < arr.GetLength(1); j++)
{
for (int k = 0; k < arr.GetLength(2); k++)
{
Console.Write(arr[i, j, k] + " ");
}
Console.WriteLine();
}
Console.WriteLine();
}
Console.WriteLine();
}} //This code is contributed bu Akash Jha
` JavaScript ``
const R = 3, C = 3, H = 3;
function sortfun(arr) { // One by one sort individual rows. for (let i = 0; i < H; i++) for (let j = 0; j < R; j++) arr[i][j].sort();
// Printing the sorted matrix
for (let i = 0; i < H; i++) {
console.log(Layer ${i + 1}:);
for (let j = 0; j < R; j++) {
console.log(arr[i][j].join(' '));
}
}
}
let arr = [ [ [3, 2, 1], [6, 5, 4], [9, 8, 7] ], [ [11, 12, 13], [14, 15, 16], [17, 18, 19] ], [ [21, 22, 23], [24, 25, 26], [27, 28, 29] ] ];
sortfun(arr);
``
Output
Layer 1: 1 2 3 4 5 6 7 8 9 Layer 2: 11 12 13 14 15 16 17 18 19 Layer 3: 21 22 23 24 25 26 27 28 29