Check if two arrays are permutations of each other using Mathematical Operation

Given two unsorted arrays of same size, the task is to check if two arrays are permutations of each other or not.

Examples:

Input: arr1[] = {2, 1, 3, 5, 4, 3, 2}
       arr2[] = {3, 2, 2, 4, 5, 3, 1}
Output: Yes

Input: arr1[] = {2, 1, 3, 5}
       arr2[] = {3, 2, 2, 4}
Output: No

It has been already discussed in Check if two arrays are permutations of each other using Sorting and Hashing. But in this post, a different approach is discussed.

Approach:

  1. Traverse the first array A, add and multiply all the elements and store them in variables as Sum1 and Mul1 respectively.
  2. Similarly, traverse the second array B, add and multiply all the elements and store them in variables as Sum2 and Mul2 respectively.
  3. Now, compare both sum1, sum2 and mul1, mul2. If Sum1 == Sum2 and Mul1 == Mul2, then both arrays are permutations of each other, else not.


Below is the implementation of above approach:

C++

// CPP code to check if arrays
// are permutations of eah other
#include <iostream>
using namespace std;
  
// Function to check if arrays
// are permutaitons of each other.
bool arePermutations(int a[], int b[], int n, int m)
{
  
    int sum1 = 0, sum2 = 0, mul1 = 1, mul2 = 1;
  
    // Calculating sum and multiply of first array
    for (int i = 0; i < n; i++) {
        sum1 += a[i];
        mul1 *= a[i];
    }
  
    // Calculating sum and multiply of second array
    for (int i = 0; i < m; i++) {
        sum2 += b[i];
        mul2 *= b[i];
    }
  
    // If sum and mul of both arrays are equal,
    // return true, else return false.
    return ((sum1 == sum2) && (mul1 == mul2));
}
  
// Driver code
int main()
{
  
    int a[] = { 1, 3, 2 };
    int b[] = { 3, 1, 2 };
  
    int n = sizeof(a) / sizeof(int);
    int m = sizeof(b) / sizeof(int);
  
    if (arePermutations(a, b, n, m)) 
        cout << "Yes" << endl;
      
    else
        cout << "No" << endl;
  
    return 0;
}

Java

// Java code to check if arrays
// are permutations of eah other
  
import java.io.*;
  
class GFG {
  
  
// Function to check if arrays
// are permutaitons of each other.
static boolean arePermutations(int a[], int b[], int n, int m)
{
  
    int sum1 = 0, sum2 = 0, mul1 = 1, mul2 = 1;
  
    // Calculating sum and multiply of first array
    for (int i = 0; i < n; i++) {
        sum1 += a[i];
        mul1 *= a[i];
    }
  
    // Calculating sum and multiply of second array
    for (int i = 0; i < m; i++) {
        sum2 += b[i];
        mul2 *= b[i];
    }
  
    // If sum and mul of both arrays are equal,
    // return true, else return false.
    return ((sum1 == sum2) && (mul1 == mul2));
}
  
// Driver code
  
    public static void main (String[] args) {
            int a[] = { 1, 3, 2 };
    int b[] = { 3, 1, 2 };
  
    int n = a.length;
    int m = b.length;
  
    if (arePermutations(a, b, n, m)==true
        System.out.println( "Yes");
      
    else
        System.out.println( "No");
    }
}
// This code is contributed by  inder_verma..

Python 3

# Python 3 program to check if arrays 
# are permutations of eah other 
  
# Function to check if arrays 
# are permutaitons of each other
def arePermutations(a, b, n, m) :
  
    sum1, sum2, mul1, mul2 = 0, 0, 1, 1
  
    # Calculating sum and multiply of first array 
    for i in range(n) :
        sum1 += a[i]
        mul1 *= a[i]
  
    # Calculating sum and multiply of second array 
    for i in range(m) :
        sum2 += b[i]
        mul2 *= b[i]
  
    # If sum and mul of both arrays are equal, 
    # return true, else return false.
    return((sum1 == sum2) and (mul1 == mul2))
  
  
# Driver code     
if __name__ == "__main__" :
  
    a = [ 1, 3, 2]
    b = [ 3, 1, 2]
  
    n = len(a)
    m = len(b)
  
    if arePermutations(a, b, n, m) :
        print("Yes")
  
    else :
        print("No")
  
   
# This code is contributed by ANKITRAI1

C#

// C# code to check if arrays
// are permutations of eah other
using System;
  
class GFG 
{
  
// Function to check if arrays
// are permutaitons of each other.
static bool arePermutations(int[] a, int[] b, 
                            int n, int m)
{
  
    int sum1 = 0, sum2 = 0,
        mul1 = 1, mul2 = 1;
  
    // Calculating sum and multiply 
    // of first array
    for (int i = 0; i < n; i++)
    {
        sum1 += a[i];
        mul1 *= a[i];
    }
  
    // Calculating sum and multiply
    // of second array
    for (int i = 0; i < m; i++)
    {
        sum2 += b[i];
        mul2 *= b[i];
    }
  
    // If sum and mul of both arrays 
    // are equal, return true, else 
    // return false.
    return ((sum1 == sum2) &&
            (mul1 == mul2));
}
  
// Driver code
public static void Main ()
{
    int[] a = { 1, 3, 2 };
    int[] b = { 3, 1, 2 };
      
    int n = a.Length;
    int m = b.Length;
      
    if (arePermutations(a, b, n, m) == true
        Console.Write( "Yes");
      
    else
        Console.Write( "No");
}
}
  
// This code is contributed 
// by ChitraNayal

PHP

Output:

Yes

Note: It wouldn’t work for large numbers.



My Personal Notes arrow_drop_up


Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.