arrQ.cpp

// C++ program to Find another array 
// such that the hamming distance 
// from the original array is maximum 
#include <bits/stdc++.h> 
using namespace std; 

// Return the maximum hamming distance of a rotation 
int maxHamming(int arr[], int n) 
{ 
	// arr[] to brr[] two times so that 
	// we can traverse through all rotations. 
	int brr[2 *n + 1]; 
	for (int i = 0; i < n; i++) 
		brr[i] = arr[i]; 
	for (int i = 0; i < n; i++) 
		brr[n+i] = arr[i]; 

	// We know hamming distance with 0 rotation 
	// would be 0. 
	int maxHam = 0;	 

	// We try other rotations one by one and compute 
	// Hamming distance of every rotation 
	for (int i = 1; i < n; i++) 
	{ 
		int currHam = 0; 
		for (int j = i, k=0; j < (i + n); j++,k++) 
			if (brr[j] != arr[k]) 
				currHam++; 

		// We can never get more than n. 
		if (currHam == n) 
			return n; 

		maxHam = max(maxHam, currHam); 
	} 

	return maxHam; 
} 

// driver program 
int main() 
{ 
	int arr[] = {2, 4, 6, 8};	 
	int n = sizeof(arr)/sizeof(arr[0]); 
	cout << maxHamming(arr, n);	 
	return 0; 
}