Given an integer array arr[], the task is to sort only those elements which are ugly numbers at their relative positions in the array (positions of other elements must not be affected).
Ugly numbers are numbers whose only prime factors are 2, 3 or 5.
The sequence 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, ….. shows first few ugly numbers. By convention, 1 is included.
Examples:
Input: arr[] = {13, 9, 11, 3, 2}
Output: 13 2 11 3 9
9, 3 and 2 are the only ugly numbers in the given array.
Input: arr[] = {1, 2, 3, 7, 12, 10}
Output: 1 2 3 7 10 12
Approach:
- Start traversing the array and for every element arr[i], if arr[i] is an ugly number then store it in an ArrayList and update arr[i] = -1
- After all the ugly numbers have been stored in the ArrayList, sort the updated ArrayList.
- Again traverse the array and for every element,
- If arr[i] = -1 then print the first element from the ArrayList that hasn’t been printed before.
- Else, print arr[i].
Below is the implementation of the above approach:
// CPP implementation of the approach #include<bits/stdc++.h> using namespace std;
// Function that returns true if n is an ugly number bool isUgly( int n)
{ // While divisible by 2, keep dividing
while (n % 2 == 0)
n = n / 2;
// While divisible by 3, keep dividing
while (n % 3 == 0)
n = n / 3;
// While divisible by 5, keep dividing
while (n % 5 == 0)
n = n / 5;
// n must be 1 if it was ugly
if (n == 1)
return true ;
return false ;
} // Function to sort ugly numbers // in their relative positions void sortUglyNumbers( int arr[], int n)
{ // To store the ugly numbers from the array
vector< int > list;
int i;
for (i = 0; i < n; i++)
{
// If current element is an ugly number
if (isUgly(arr[i]))
{
// Add it to the ArrayList
// and set arr[i] to -1
list.push_back(arr[i]);
arr[i] = -1;
}
}
// Sort the ugly numbers
sort(list.begin(),list.end());
int j = 0;
for (i = 0; i < n; i++)
{
// Position of an ugly number
if (arr[i] == -1)
cout << list[j++] << " " ;
else
cout << arr[i] << " " ;
}
} // Driver code int main()
{ int arr[] = { 1, 2, 3, 7, 12, 10 };
int n = sizeof (arr)/ sizeof (arr[0]);
sortUglyNumbers(arr, n);
} // This code is contributed by // Surendra_Gangwar |
// Java implementation of the approach import java.util.ArrayList;
import java.util.Collections;
class GFG {
// Function that returns true if n is an ugly number
static boolean isUgly( int n)
{
// While divisible by 2, keep dividing
while (n % 2 == 0 )
n = n / 2 ;
// While divisible by 3, keep dividing
while (n % 3 == 0 )
n = n / 3 ;
// While divisible by 5, keep dividing
while (n % 5 == 0 )
n = n / 5 ;
// n must be 1 if it was ugly
if (n == 1 )
return true ;
return false ;
}
// Function to sort ugly numbers
// in their relative positions
static void sortUglyNumbers( int arr[], int n)
{
// To store the ugly numbers from the array
ArrayList<Integer> list = new ArrayList<>();
int i;
for (i = 0 ; i < n; i++) {
// If current element is an ugly number
if (isUgly(arr[i])) {
// Add it to the ArrayList
// and set arr[i] to -1
list.add(arr[i]);
arr[i] = - 1 ;
}
}
// Sort the ugly numbers
Collections.sort(list);
int j = 0 ;
for (i = 0 ; i < n; i++) {
// Position of an ugly number
if (arr[i] == - 1 )
System.out.print(list.get(j++) + " " );
else
System.out.print(arr[i] + " " );
}
}
// Driver code
public static void main(String[] args)
{
int arr[] = { 1 , 2 , 3 , 7 , 12 , 10 };
int n = arr.length;
sortUglyNumbers(arr, n);
}
} |
# Python3 implementation of the approach # Function that returns true if n is an ugly number def isUgly(n):
# While divisible by 2, keep dividing
while n % 2 = = 0 :
n = n / / 2
# While divisible by 3, keep dividing
while n % 3 = = 0 :
n = n / / 3
# While divisible by 5, keep dividing
while n % 5 = = 0 :
n = n / / 5
# n must be 1 if it was ugly
if n = = 1 :
return True
return False
# Function to sort ugly numbers # in their relative positions def sortUglyNumbers(arr, n):
# To store the ugly numbers from the array
list = []
for i in range ( 0 , n):
# If current element is an ugly number
if isUgly(arr[i]):
# Add it to the ArrayList
# and set arr[i] to -1
list .append(arr[i])
arr[i] = - 1
# Sort the ugly numbers
list .sort()
j = 0
for i in range ( 0 , n):
# Position of an ugly number
if arr[i] = = - 1 :
print ( list [j], end = " " )
j + = 1
else :
print (arr[i], end = " " )
# Driver code if __name__ = = "__main__" :
arr = [ 1 , 2 , 3 , 7 , 12 , 10 ]
n = len (arr)
sortUglyNumbers(arr, n)
# This code is contributed by Rituraj Jain |
// C# implementation of the approach using System;
using System.Collections.Generic;
class GFG
{ // Function that returns true
// if n is an ugly number
static bool isUgly( int n)
{
// While divisible by 2, keep dividing
while (n % 2 == 0)
n = n / 2;
// While divisible by 3, keep dividing
while (n % 3 == 0)
n = n / 3;
// While divisible by 5, keep dividing
while (n % 5 == 0)
n = n / 5;
// n must be 1 if it was ugly
if (n == 1)
return true ;
return false ;
}
// Function to sort ugly numbers
// in their relative positions
static void sortUglyNumbers( int []arr, int n)
{
// To store the ugly numbers from the array
List< int > list = new List< int >();
int i;
for (i = 0; i < n; i++)
{
// If current element is an ugly number
if (isUgly(arr[i]))
{
// Add it to the ArrayList
// and set arr[i] to -1
list.Add(arr[i]);
arr[i] = -1;
}
}
// Sort the ugly numbers
list.Sort();
int j = 0;
for (i = 0; i < n; i++)
{
// Position of an ugly number
if (arr[i] == -1)
Console.Write(list[j++] + " " );
else
Console.Write(arr[i] + " " );
}
}
// Driver code
public static void Main(String[] args)
{
int []arr = { 1, 2, 3, 7, 12, 10 };
int n = arr.Length;
sortUglyNumbers(arr, n);
}
} // This code contributed by Rajput-Ji |
<script> // Javascript implementation of the approach // Function that returns true if n is an ugly number function isUgly(n)
{ // While divisible by 2, keep dividing
while (n % 2 == 0)
n = n / 2;
// While divisible by 3, keep dividing
while (n % 3 == 0)
n = n / 3;
// While divisible by 5, keep dividing
while (n % 5 == 0)
n = n / 5;
// n must be 1 if it was ugly
if (n == 1)
return true ;
return false ;
} // Function to sort ugly numbers // in their relative positions function sortUglyNumbers(arr, n)
{ // To store the ugly numbers from the array
var list = [];
var i;
for (i = 0; i < n; i++)
{
// If current element is an ugly number
if (isUgly(arr[i]))
{
// Add it to the ArrayList
// and set arr[i] to -1
list.push(arr[i]);
arr[i] = -1;
}
}
// Sort the ugly numbers
list.sort((a,b)=>a-b);
var j = 0;
for (i = 0; i < n; i++)
{
// Position of an ugly number
if (arr[i] == -1)
document.write( list[j++] + " " );
else
document.write( arr[i] + " " );
}
} // Driver code var arr = [1, 2, 3, 7, 12, 10 ];
var n = arr.length;
sortUglyNumbers(arr, n); </script> |
1 2 3 7 10 12
Time Complexity: O(nlog(n))
Auxiliary Space: O(n)