arr [ i ] cannot make s pair with itself i . e . ( arr [ i ] , arr [ i ] )
if ( i == j ) : NEW_LINE INDENT cnt += ( ( bitMask [ i ] * bitMask [ i ] - 1 ) // 2 ) NEW_LINE DEDENT else : NEW_LINE INDENT cnt += ( bitMask [ i ] * bitMask [ j ] ) NEW_LINE DEDENT return cnt NEW_LINE