Given an array arr[] of n elements, we have to swap an index i with another index i + k any number of times and check whether it is possible to sort the given array arr[]. If it is then print “yes” otherwise print “no”.
Examples:
Input: K = 2, arr = [4, 3, 2, 6, 7]
Output: Yes
Explanation:
Choose index i = 0 and swap index i with i + k then the array becomes [2, 3, 4, 6, 7] which is sorted hence the output is “yes”.
Input : K = 2, arr = [4, 2, 3, 7, 6]
Output : No
Explanation:
It is not possible to obtain sorted array.
Approach:
To solve the problem mentioned above we have to take the elements starting from index 0 and add the multiples of K to it, that is 0, 0 + k, 0 + (2*k), and so on. Swap these positions for all the indexes from 0 to K-1 and check if the final array is sorted. If it is, then return “yes” otherwise “no”.
Below is the implementation of the above approach:
C++
// CPP implementation to Check if it is possible to sort an // array with conditional swapping of elements at distance K #include <bits/stdc++.h> using namespace std; // Function for finding if it possible // to obtain sorted array or not bool fun( int arr[], int n, int k) { vector< int > v; // Iterate over all elements until K for ( int i = 0; i < k; i++) { // Store elements as multiples of K for ( int j = i; j < n; j += k) { v.push_back(arr[j]); } // Sort the elements sort(v.begin(), v.end()); int x = 0; // Put elements in their required position for ( int j = i; j < n; j += k) { arr[j] = v[x]; x++; } v.clear(); } // Check if the array becomes sorted or not for ( int i = 0; i < n - 1; i++) { if (arr[i] > arr[i + 1]) return false ; } return true ; } // Driver code int main() { int arr[] = { 4, 2, 3, 7, 6 }; int K = 2; int n = sizeof (arr) / sizeof (arr[0]); if (fun(arr, n, K)) cout << "yes" << endl; else cout << "no" << endl; return 0; } |
Java
// Java implementation to check if it // is possible to sort an array with // conditional swapping of elements // at distance K import java.lang.*; import java.io.*; import java.util.*; class GFG{ // Function for finding if it possible // to obtain sorted array or not public static boolean fun( int [] arr, int n, int k) { Vector<Integer> v = new Vector<Integer>(); // Iterate over all elements until K for ( int i = 0 ; i < k; i++) { // Store elements as multiples of K for ( int j = i; j < n; j += k) { v.add(arr[j]); } // Sort the elements Collections.sort(v); int x = 0 ; // Put elements in their // required position for ( int j = i; j < n; j += k) { arr[j] = v.get(x); x++; } v.clear(); } // Check if the array becomes // sorted or not for ( int i = 0 ; i < n - 1 ; i++) { if (arr[i] > arr[i + 1 ]) { return false ; } } return true ; } // Driver code public static void main (String args[]) { int [] arr = { 4 , 2 , 3 , 7 , 6 }; int K = 2 ; int n = arr.length; if (fun(arr, n, K)) { System.out.println( "yes" ); } else { System.out.println( "no" ); } } } // This code is contributed by sayesha |
Python3
# Python3 implementation to Check if it is possible to sort an # array with conditional swapping of elements at distance K # Function for finding if it possible # to obtain sorted array or not def fun(arr, n, k): v = [] # Iterate over all elements until K for i in range (k): # Store elements as multiples of K for j in range (i, n, k): v.append(arr[j]); # Sort the elements v.sort(); x = 0 # Put elements in their required position for j in range (i, n, k): arr[j] = v[x]; x + = 1 v = [] # Check if the array becomes sorted or not for i in range (n - 1 ): if (arr[i] > arr[i + 1 ]): return False return True # Driver code arr = [ 4 , 2 , 3 , 7 , 6 ] K = 2 ; n = len (arr) if (fun(arr, n, K)): print ( "yes" ) else : print ( "no" ) # This code is contributed by apurva raj |
C#
// C# implementation to check if it // is possible to sort an array with // conditional swapping of elements // at distance K using System; using System.Collections.Generic; class GFG{ // Function for finding if it possible // to obtain sorted array or not public static bool fun( int [] arr, int n, int k) { List< int > v = new List< int >(); // Iterate over all elements until K for ( int i = 0; i < k; i++) { // Store elements as multiples of K for ( int j = i; j < n; j += k) { v.Add(arr[j]); } // Sort the elements v.Sort(); int x = 0; // Put elements in their // required position for ( int j = i; j < n; j += k) { arr[j] = v[x]; x++; } v.Clear(); } // Check if the array becomes // sorted or not for ( int i = 0; i < n - 1; i++) { if (arr[i] > arr[i + 1]) { return false ; } } return true ; } // Driver code public static void Main(String []args) { int [] arr = {4, 2, 3, 7, 6}; int K = 2; int n = arr.Length; if (fun(arr, n, K)) { Console.WriteLine( "yes" ); } else { Console.WriteLine( "no" ); } } } // This code is contributed by shikhasingrajput |
Javascript
<script> // JavaScript implementation to // Check if it is possible to sort an // array with conditional swapping of // elements at distance K // Function for finding if it possible // to obtain sorted array or not function fun(arr, n, k) { let v = []; // Iterate over all elements until K for (let i = 0; i < k; i++) { // Store elements as multiples of K for (let j = i; j < n; j += k) { v.push(arr[j]); } // Sort the elements v.sort(); let x = 0; // Put elements in their required position for (let j = i; j < n; j += k) { arr[j] = v[x]; x++; } v = []; } // Check if the array becomes sorted or not for (let i = 0; i < n - 1; i++) { if (arr[i] > arr[i + 1]) return false ; } return true ; } // Driver code let arr = [ 4, 2, 3, 7, 6 ]; let K = 2; let n = arr.length; if (fun(arr, n, K)) document.write( "yes" ); else document.write( "no" ); </script> |
no
Time Complexity: O(k*n*log(n))
Auxiliary Space: O(n)
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