Imprimir elementos distintos ordenados de la array

Dada una array que podría contener duplicados, imprima todos los elementos distintos en orden ordenado.

Ejemplos: 

Input  : 1, 3, 2, 2, 1
Output : 1 2 3

Input  : 1, 1, 1, 2, 2, 3
Output : 1 2 3

La solución simple es ordenar la array primero, luego atravesar la array e imprimir solo las primeras apariciones de elementos.

Otro enfoque es usar set en C++ STL .  

// CPP program to print sorted distinct
// elements.
#include <bits/stdc++.h>
using namespace std;
 
void printRepeating(int arr[], int size)
{
    // Create a set using array elements
    set<int> s(arr, arr + size);
 
    // Print contents of the set.
    for (auto x : s)
        cout << x << " ";
}
 
// Driver code
int main()
{
    int arr[] = { 1, 3, 2, 2, 1 };
    int n = sizeof(arr) / sizeof(arr[0]);
    printRepeating(arr, n);
    return 0;
}

// Java program to print sorted distinct
// elements.
import java.io.*;
import java.util.*;
 
public class GFG {
      
    static void printRepeating(Integer []arr, int size)
    {
        // Create a set using array elements
        SortedSet<Integer> s = new TreeSet<>();
        Collections.addAll(s, arr);
         
        // Print contents of the set.
        System.out.print(s);
    }
      
    // Driver code
    public static void main(String args[])
    {
        Integer []arr = {1, 3, 2, 2, 1};
        int n = arr.length;
        printRepeating(arr, n);
    }
}
  
// This code is contributed by
// Manish Shaw (manishshaw1)

# Python3 program to print
# sorted distinct elements.
 
def printRepeating(arr,size):
 
    # Create a set using array elements
    s = set()
    for i in range(size):
        if arr[i] not in s:
            s.add(arr[i])
 
    # Print contents of the set.
    for i in s:
        print(i,end=" ")
 
# Driver code
if __name__=='__main__':
    arr = [1,3,2,2,1]
    size = len(arr)
    printRepeating(arr,size)
 
# This code is contributed by
# Shrikant13

// C# program to print sorted distinct
// elements.
using System;
using System.Collections.Generic;
using System.Linq;
 
class GFG {
     
    static void printRepeating(int []arr, int size)
    {
        // Create a set using array elements
        SortedSet<int> s = new SortedSet<int>(arr);
     
        // Print contents of the set.
        foreach (var n in s)
        {
            Console.Write(n + " ");
        }
    }
     
    // Driver code
    public static void Main()
    {
        int []arr = {1, 3, 2, 2, 1};
        int n = arr.Length;
        printRepeating(arr, n);
    }
}
 
// This code is contributed by
// Manish Shaw (manishshaw1)

<script>
 
// Javascript program to print sorted distinct
// elements.
function printRepeating(arr, size)
{
     
    // Create a set using array elements
    var s = new Set(arr);
 
    // Print contents of the set.
    [...s].sort((a, b) => a - b).forEach(x => {
        document.write(x + " ")
    });
}
 
// Driver code
var arr = [ 1, 3, 2, 2, 1 ];
var n = arr.length;
 
printRepeating(arr, n);
 
// This code is contributed by itsok
 
</script>

1 2 3

Complejidad de tiempo: O (nlogn).

Espacio Auxiliar: O(n)