Can u please tell me why are we doing this

#1 
    lbest[i] = max( (i == 0)? 0 : lbest[i-1] , tl.findMaxXorPair(left_value));
#2

lbest[i] = will tell u max xor subarray when array [0
i] is considered

so we need to find the max bw lbest[i-1] and maxxorpair for leftvalue