Row wise sorting a 2D array

Last Updated : 03 Apr, 2025

Given a 2D array, sort each row of this array and print the result.

Examples:

Input : mar[][] = [ [77, 11, 22, 3],
[11, 89, 1, 12],
[32, 11, 56, 7],
[11, 22, 44, 33] ]
Output : mat[][] = [ [3, 11, 22, 77],
[1, 11, 12, 89],
[7, 11, 32, 56],
[11, 22, 33, 44] ]

Input : mat[][] = [ [8, 6, 4, 5],
[3, 5, 2, 1],
[9, 7, 4, 2],
[7, 8, 9, 5] ]
Output :mat[][] = [ [4, 5, 6, 8],
[1, 2, 3, 5],
[2, 4, 7, 9],
[5, 7, 8, 9] ]

The idea is simple, we traverse through each row and call sort for it. Below are sort functions for reference in different languages.
Arrays.sort() in Java
sort() in C++
sort() in Python
sort() in JavaScript
sort() in PHP
qsort() in C

C++

#include <bits/stdc++.h> using namespace std;  void sortRows(vector<vector<int>> &mat) {   for (auto &row : mat)     sort(row.begin(), row.end()); }  int main() {   vector<vector<int>> mat = {       {77, 11, 22, 3},       {11, 89, 1, 12},       {32, 11, 56, 7},       {11, 22, 44, 33}};    sortRows(mat);    cout << "[\n";   for (auto &row : mat) {     cout << "  [";     for (int j = 0; j < row.size(); j++) {       if (j > 0) cout << ", ";       cout << row[j];     }     cout << "]\n";   }   cout << "]\n"; }

#include <stdio.h>  #define ROWS 4 #define COLS 4  void sortRow(int row[], int n) {     for (int i = 0; i < n - 1; i++) {         for (int j = 0; j < n - i - 1; j++) {             if (row[j] > row[j + 1]) {                 int temp = row[j];                 row[j] = row[j + 1];                 row[j + 1] = temp;             }         }     } }  void sortRows(int mat[ROWS][COLS]) {     for (int i = 0; i < ROWS; i++) {         sortRow(mat[i], COLS);     } }  int main() {     int mat[ROWS][COLS] = {         {77, 11, 22, 3},         {11, 89, 1, 12},         {32, 11, 56, 7},         {11, 22, 44, 33}     };      sortRows(mat);      printf("[\n");     for (int i = 0; i < ROWS; i++) {         printf("  [");         for (int j = 0; j < COLS; j++) {             if (j > 0) printf(", ");             printf("%d", mat[i][j]);         }         printf("]\n");     }     printf("]\n");      return 0; }

Java

import java.util.Arrays; import java.util.Collections;  public class Main {     public static void sortRows(int[][] mat) {         for (int[] row : mat) {             Arrays.sort(row);         }     }      public static void main(String[] args) {         int[][] mat = {             {77, 11, 22, 3},             {11, 89, 1, 12},             {32, 11, 56, 7},             {11, 22, 44, 33}         };          sortRows(mat);          System.out.println("[");         for (int[] row : mat) {             System.out.print("  [");             for (int j = 0; j < row.length; j++) {                 if (j > 0) System.out.print(", ");                 System.out.print(row[j]);             }             System.out.println("]");         }         System.out.println("]");     } }

Python

def sortRows(mat):     for row in mat:         row.sort()  mat = [     [77, 11, 22, 3],     [11, 89, 1, 12],     [32, 11, 56, 7],     [11, 22, 44, 33] ]  sortRows(mat)  print('[\n', end='') for row in mat:     print('  [', end='')     print(', '.join(map(str, row)), end='')     print(']') print(']')

using System; using System.Collections.Generic;  class Program {     static void SortRows(List<List<int>> mat)     {         foreach (var row in mat)         {             row.Sort();         }     }      static void Main()     {         var mat = new List<List<int>>         {             new List<int> { 77, 11, 22, 3 },             new List<int> { 11, 89, 1, 12 },             new List<int> { 32, 11, 56, 7 },             new List<int> { 11, 22, 44, 33 }         };          SortRows(mat);          Console.WriteLine("[");         foreach (var row in mat)         {             Console.Write("  [");             for (int j = 0; j < row.Count; j++)             {                 if (j > 0) Console.Write(", ");                 Console.Write(row[j]);             }             Console.WriteLine("]");         }         Console.WriteLine("]");     } }

JavaScript

function sortRows(mat) {     for (let row of mat) {         row.sort((a, b) => a - b);     } }  let mat = [     [77, 11, 22, 3],     [11, 89, 1, 12],     [32, 11, 56, 7],     [11, 22, 44, 33] ];  sortRows(mat);  console.log('[\n'); for (let row of mat) {     console.log('  [', row.join(', '), ']'); } console.log(']');

Output

[   [3, 11, 22, 77]   [1, 11, 12, 89]   [7, 11, 32, 56]   [11, 22, 33, 44] ]

Time Complexity: O(r*c*log(c)) where r is the number of rows and c is the number of columns.
Auxiliary Space: O(1)

Row wise sorting a 2D array

Shivani2609

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Row wise sorting a 2D array

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