Can't able to find approach for this question

#1

can’t able to find approach for this question

#2

hi divyam there is a unique approach to do that question using bit approach
first u have to take the xor of all the element like take element
1 1 2 2 3 4
now u have the xor of 3 and 4 remaining
now find the first set bit in this and then take xor of all the element
each of 1 1 2 2 either have that bit set or unset so they will be divided into two group
like 1 1 and 2 2
but 3 and 4 have this bit different (thats why this bit is set in taking xor of all element)
so they fall in different group
like 1 1 3 and 2 2 4
now take xor of these different group seperately u will the ans
first run this method in a copy for above example

if u r not understand this watch the video in the course u will get clear

#3

can’t understand pls elaborate

#4

Have u watched the video of the unique number 2 in the course??