import java.util.*; public class KnightToureRandom { static int base=8, fields=base*base; static int[][]moves={{1,-2},{2,-1},{2,1},{1,2},{-1,2},{-2,1},{-2,-1},{-1,-2}}; static int[][]board; public static void main(String[] args){ board=new int[base][base]; int startPosRow=(int)(Math.random()*base); int startPosCol=(int)(Math.random()*base); board[startPosRow][startPosCol] = 0; if (visitAll(0,startPosRow, startPosCol)) printResult(); else System.out.printf("For board %dx%d with (%d,%d) as start position, result is impossible", base, base, startPosRow+1, startPosCol+1);; } static boolean visitAll(int count,int row,int col){ if (count > fields) { for (int[] b : board) if(contains(b, 0)) return false; return true; } List arr=fillAround(row, col); if (arr.isEmpty()&&count!=fields) return false; Collections.sort(arr,(int[]i,int[]j)-> i[2]-j[2]); for (int[]ar:arr) { row=ar[0]; col=ar[1]; board[row][col]=count; if (isVisited(count,row,col)&& visitAll(++count,row,col)) { for (int[] b : board) if(contains(b, 0)) return false; return true; } board[row][col]=0; } return false; } static List fillAround(int row,int col) { Listarr=new ArrayList<>(); for(int[]m:moves) { int i=m[0]; int j=m[1]; if(row+j-1&&col+i>-1) {if(board[row+j][col+i]==0) { int n=calculateAround (row+j,col+i); arr.add(new int[]{row+j,col+i,n}); } } } return arr; } static int calculateAround(int row,int col) { int i=0; for (int[]m:moves) if(row+m[1]-1&&col+m[0]-1) {if(board[row+m[1]][col+m[0]]==0) i++;} return i; } static boolean isVisited(int count,int row,int col) { if (countarr=fillAround(row,col); for(int[]ar:arr) if(calculateAround(ar[0],ar [1])==0) return false; } return true; } static boolean contains(int[] arr, int item) { for (int n : arr) if (item == n) return true; return false; } static void printResult() { for (int[]row:board) { for (int i:row) System.out.printf("%2d ", i); System.out.println(); } } }

KnightsRandom