Solve SEND+MORE=MONEY puzzle with Java

SendMoreMoney.java

import java.util.Arrays;

public class SendMoreMoney {
	
	public static void main(String[] args) {
		SendMoreMoney smm = new SendMoreMoney();
		
		System.out.println("[s, e, n, d, m, o, r, y]");
		System.out.println(Arrays.toString(smm.solve()));
	}
  
	/*
	 *	    S E N D
	 * 	+   M O R E
	 * ------------
	 * 	  M O N E Y
	 * where M != 0 and every digit stands for a different (unique) number
	 */
	
	private int[] solve() {
		int[] result = null;
		
		for(int s = 0; s <= 9; s++) {
			for(int e = 0; e <= 9; e++) {
				for(int n = 0; n <= 9; n++) {
					for(int d = 0; d <= 9; d++) {
						for(int m = 1; m <= 9; m++) { // [sic!]
							for(int o = 0; o <= 9; o++) {
								for(int r = 0; r <= 9; r++) {
									for(int y = 0; y <= 9; y++) {
										// ------------------------------------------------
										// Does sum of SEND and MORE match MONEY?
										if(	               s*1000 + e*100 + n*10 + d
											   +           m*1000 + o*100 + r*10 + e
											  == m*10000 + o*1000 + n*100 + e*10 + y) {
										
											// Then put digits into result array
											result = new int[] {s,e,n,d,m,o,r,y};
											
											// Check if elements are also unique
											if(elementsUnique(result)) {
												// True? That's our solution!
												return result;
											}
											// else continue
										}
										// else continue
										// ------------------------------------------------
									}
								}
							}
						}
					}
				}
			}
		}
		
		// we should never reach this line
		return null;
	}
	
	private boolean elementsUnique(int[] arr) {
		// Make a temporary copy of our result array to keep the order
    		int[] copyOfArr = new int[arr.length];
		System.arraycopy(arr, 0, copyOfArr, 0, arr.length);
    
    		// Sort
		Arrays.sort(copyOfArr);
    		// Check for pairwise dissimilarity
		return isPairwiseDifferent(copyOfArr, 0);
	}
	
	private boolean isPairwiseDifferent(int[] arr, int p) {
		if(p == arr.length - 1) {
			return true;
		}
		return arr[p] != arr[p+1] && isPairwiseDifferent(arr, p+1);
	}

}