Selecting the triplets such that elements of the pairs ( arr [ 0 ] , arr [ 1 ] ) , ( arr [ 2 ] , arr [ 3 ] ) . . . can be made equal
for ( int i = 0 ; i < N - 2 ; i += 2 ) { System . out . println ( i + " ▁ " + ( i + 1 ) + " ▁ " + ( i + 2 ) ) ; }