This input:
[6, 1, 4, 3, 5]
[3, 8, 4, 2, 2]
Gives correct Expected answer 2
Now, I assume, that this input should give answer 1
:
[6, 1, 4, 3, 5]
[3, 8, 4, 3, 2]
however, Expected Answer
is 2
. Why? If you calculate the total gas amount available  19
and total gas amount required  20
one shouldn't be able to complete the circuit regardless of the starting station, right?. Unless I misunderstand the problem statement...
Additionally, if you change 8
to 9
or 10
in the input array, it still gives expected answer 2
. Only if you change 8
to 11
it says 1
:

#1:
 Input:
[6, 1, 4, 3, 5] [3, 9, 4, 3, 2]
 Given "Expected Answer" by leetcode:
2
 What is really expected (correct answer):
1
 Input:

#2:
 Input:
[6, 1, 4, 3, 5] [3, 10, 4, 3, 2]
 Given "Expected Answer" by leetcode:
2
 What is really expected (correct answer):
1

#3:
 Input:
[6, 1, 4, 3, 5] [3, 11, 4, 3, 2]
 Given "Expected Answer" by leetcode:
1
 What is really expected (correct answer):
1
Any thoughts?