# remove duplicates from array [closed]

You have given an array from which we need to remove duplicates.

Rules:

1. First or immediate duplicates gets removed first.

2. Array contains natural numbers a[i]>0 for i>=0

3. no. of elements in the array is greater than 1 i.e. n>1

e.g.

{1,2,3,4,5,5,4,6,6,7,8}=> {1,2,3,7,8}
{1,2,3,3,4,5,6,7,7,8} => {1,2,4,5,6,8}
{1,1,3,3,4,4,6,6}=>{}
{4,2,6,8,3,1,1,3,8,6,2,4}=>{}
{6,6,6,1}=>{6,1}


Only adjacent duplicate elements like [1, 2, 2, 1] are removed, but not [1, 2, 1, 2]. This process is repeated until no further modifications are made.

For winning criteria is the one which gives the fastest result.

## closed as off-topic by Dennis♦Jul 15 '17 at 18:57

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "Questions without an objective primary winning criterion are off-topic, as they make it impossible to indisputably decide which entry should win." – Dennis
If this question can be reworded to fit the rules in the help center, please edit the question.

• You must specify the winning criterion clearly in your post. – Mr. Xcoder Jul 15 '17 at 17:53
• Why {6,1}? 6 is a duplicate. Then, {1,2,3,4,5,5,4,6,6,7,8} should output {1,2,3,4,5,6,7,8} as well. – Mr. Xcoder Jul 15 '17 at 18:00
• @SatishPatel You should specify that in the challenge. – Mr. Xcoder Jul 15 '17 at 18:02
• Also, I suggest making it code-golf. – Mr. Xcoder Jul 15 '17 at 18:02
• If you want to keep this as fastest ode (which is fine) you'll need to provide larger test cases as yours would complete almost instantaneous in any sane language and be subject to significant noise in times – Downgoat Jul 15 '17 at 18:48

# Python 2, 201 bytes

array = input()
index = 0
while index < len(array) - 1:
if index >= 0 and array[index] == array[index + 1]:
array = array[:index] + array[index + 2:]
index -= 1
continue
index += 1
print(array)


Try it online!

Optimizations thanks to Mr. Xcoder

• I got values between 1.1126001481898129e-05 and 8.827599958749488e-05 for the test cases in the challenge. – Mr. Xcoder Jul 15 '17 at 18:24
• @Mr.Xcoder Okay, thanks. This is using bash's built in time which may be off, I don't know for sure. – HyperNeutrino Jul 15 '17 at 18:39
• I get slightly better times if I add continue at the end of your if statement and drop the else (between 1.0405001376057044e-05 and 4.7165998694254085e-05), because it skips the evaluation of the else-statement. – Mr. Xcoder Jul 15 '17 at 18:46
• @Mr.Xcoder Interesting, thanks. – HyperNeutrino Jul 15 '17 at 18:55