Given an array containing n numbers. The problem is to split the array into two subarrays such that the absolute difference of the xor values of the two subarrays is minimum.
Note: Array contains at least 2 numbers.
Examples:
Input : arr[] = {12, 6, 20, 14, 38, 6} Output : 16 The two subarrays are: {12, 6, 20} = 12 ^ 6 ^ 20 = 30 {14, 38, 6} = 14 ^ 38 ^ 6 = 46 Absolute difference = abs(30-46) = 16 Input : arr[] = {10, 16, 9, 34, 7, 46, 23} Output : 1
Naive Approach: Using two for loops find the xor values of the two subarrays sub_arr1[1..i] and sub_arr2[i+1..n] for every i = 1 to n-1. Find their absolute difference and accordingly update the minimum absolute difference.
Time Complexity: O(n2)
Efficient Approach: It is based on the following properties of the ^(xor) operator:
- a ^ 0 = a.
- a ^ a = 0.
Algorithm:
minDiffBtwXorValues(arr, n) Declare tot_xor = 0 for i = 0 to n-1 tot_xor ^= arr[i] Declare part_xor = 0 Declare min = Maximum Integer for i = 0 to n-2 tot_xor ^= arr[i] part_xor ^= arr[i] if abs(tot_xor - part_xor) < min min = abs(tot_xor - part_xor) return min
Implementation:
C++
// C++ implementation to find the minimum // absolute difference of the xor values // of the two subarrays #include <bits/stdc++.h> using namespace std; // function to find the minimum absolute // difference of the xor values of the // two subarrays int minDiffBtwXorValues( int arr[], int n) { // to store the xor value of the // entire array int tot_xor = 0; for ( int i = 0; i < n; i++) tot_xor ^= arr[i]; // 'part_xor' to store the xor value // of some subarray int part_xor = 0, min = INT_MAX; for ( int i = 0; i < n - 1; i++) { // removing the xor value of the // subarray [0..i] form 'tot_xor', // i.e, it will contain the xor // value of the subarray [i+1..n-1] tot_xor ^= arr[i]; // calculating the xor value of the // subarray [0..i] part_xor ^= arr[i]; // if absolute difference is minimum, // then update 'min' if ( abs (tot_xor - part_xor) < min) min = abs (tot_xor - part_xor); } // required minimum absolute difference return min; } // Driver program to test above int main() { int arr[] = { 12, 6, 20, 14, 38, 6 }; int n = sizeof (arr) / sizeof (arr[0]); cout << "Minimum Absolute Difference = " << minDiffBtwXorValues(arr, n); return 0; } |
Java
// Java implementation to // find the minimum // absolute difference // of the xor values // of the two subarrays import java.util.*; import java.lang.*; public class GfG{ // function to find // the minimum absolute // difference of the // xor values of the // two subarrays public static int minDiffBtwXorValues( int arr[], int n) { // to store the xor value of the // entire array int tot_xor = 0 ; for ( int i = 0 ; i < n; i++) tot_xor ^= arr[i]; // 'part_xor' to store the xor value // of some subarray int part_xor = 0 , min = Integer.MAX_VALUE; for ( int i = 0 ; i < n - 1 ; i++) { // removing the xor value of the // subarray [0..i] form 'tot_xor', // i.e, it will contain the xor // value of the subarray [i+1..n-1] tot_xor ^= arr[i]; // calculating the xor value of the // subarray [0..i] part_xor ^= arr[i]; // if absolute difference is minimum, // then update 'min' if (Math.abs(tot_xor - part_xor) < min) min = Math.abs(tot_xor - part_xor); } // required minimum absolute difference return min; } // Driver function public static void main(String argc[]){ int arr[] = { 12 , 6 , 20 , 14 , 38 , 6 }; int n = 6 ; System.out.println( "Minimum Absolute Difference = " + minDiffBtwXorValues(arr, n)); } } // This code is contributed by Sagar Shukla |
Python
# Python implementation to find the minimum # absolute difference of the xor values # of the two subarrays import sys # function to find the minimum absolute # difference of the xor values of the # two subarrays def minDiffBtwXorValues(arr, n): # to store the xor value of the # entire array tot_xor = 0 for i in range (n): tot_xor ^ = arr[i] # 'part_xor' to store the xor value # of some subarray part_xor = 0 min = sys.maxint for i in range (n - 1 ): # removing the xor value of the # subarray [0..i] form 'tot_xor', # i.e, it will contain the xor # value of the subarray [i+1..n-1] tot_xor ^ = arr[i] # calculating the xor value of the # subarray [0..i] part_xor ^ = arr[i] # if absolute difference is minimum, # then update 'min' if ( abs (tot_xor - part_xor) < min ): min = abs (tot_xor - part_xor) # required minimum absolute difference return min # Driver program to test above arr = [ 12 , 6 , 20 , 14 , 38 , 6 ] n = len (arr) print "Minimum Absolute Difference =" , minDiffBtwXorValues(arr, n) # This code is contributed by Sachin Bisht |
C#
// C# implementation to // find the minimum // absolute difference // of the xor values // of the two subarrays using System; class GFG { // function to find // the minimum absolute // difference of the // xor values of the // two subarrays public static int minDiffBtwXorValues( int [] arr, int n) { // to store the xor value of the // entire array int tot_xor = 0; for ( int i = 0; i < n; i++) tot_xor ^= arr[i]; // 'part_xor' to store the xor value // of some subarray int part_xor = 0, min = int .MaxValue; for ( int i = 0; i < n - 1; i++) { // removing the xor value of the // subarray [0..i] form 'tot_xor', // i.e, it will contain the xor // value of the subarray [i+1..n-1] tot_xor ^= arr[i]; // calculating the xor value of the // subarray [0..i] part_xor ^= arr[i]; // if absolute difference is minimum, // then update 'min' if (Math.Abs(tot_xor - part_xor) < min) min = Math.Abs(tot_xor - part_xor); } // required minimum absolute difference return min; } // Driver function public static void Main() { int [] arr = { 12, 6, 20, 14, 38, 6 }; int n = 6; Console.WriteLine( "Minimum Absolute Difference = " + minDiffBtwXorValues(arr, n)); } } // This code is contributed by Sam007 |
PHP
<?php // PHP implementation to find the minimum // absolute difference of the xor values // of the two subarrays // function to find the minimum absolute // difference of the xor values of the // two subarrays function minDiffBtwXorValues( $arr , $n ) { // to store the xor value // of the entire array $tot_xor = 0; for ( $i = 0; $i < $n ; $i ++) $tot_xor ^= $arr [ $i ]; // 'part_xor' to store the // xor value of some subarray $part_xor = 0; $min = PHP_INT_MAX; for ( $i = 0; $i < $n - 1; $i ++) { // removing the xor value of the // subarray [0..i] form 'tot_xor', // i.e, it will contain the xor // value of the subarray [i+1..n-1] $tot_xor ^= $arr [ $i ]; // calculating the xor value // of the subarray [0..i] $part_xor ^= $arr [ $i ]; // if absolute difference is // minimum, then update 'min' if ( abs ( $tot_xor - $part_xor ) < $min ) $min = abs ( $tot_xor - $part_xor ); } // required minimum // absolute difference return $min ; } // Driver Code $arr = array (12, 6, 20, 14, 38, 6); $n = count ( $arr ); echo "Minimum Absolute Difference = " , minDiffBtwXorValues( $arr , $n ); // This code is contributed by anuj_67. ?> |
Javascript
<script> // Javascript implementation to find the // minimum absolute difference of the xor // values of the two subarrays // Function to find the minimum absolute // difference of the xor values of the // two subarrays function minDiffBtwXorValues(arr, n) { // To store the xor value of the // entire array let tot_xor = 0; for (let i = 0; i < n; i++) tot_xor ^= arr[i]; // 'part_xor' to store the xor value // of some subarray let part_xor = 0, min = Number.MAX_VALUE; for (let i = 0; i < n - 1; i++) { // Removing the xor value of the // subarray [0..i] form 'tot_xor', // i.e, it will contain the xor // value of the subarray [i+1..n-1] tot_xor ^= arr[i]; // Calculating the xor value of the // subarray [0..i] part_xor ^= arr[i]; // If absolute difference is minimum, // then update 'min' if (Math.abs(tot_xor - part_xor) < min) min = Math.abs(tot_xor - part_xor); } // Required minimum absolute difference return min; } // Driver code let arr = [ 12, 6, 20, 14, 38, 6 ]; let n = arr.length; document.write( "Minimum Absolute Difference = " + minDiffBtwXorValues(arr, n)); // This code is contributed by subham348 </script> |
Minimum Absolute Difference = 16
Time Complexity: O(n)
Auxiliary Space : O(1)
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