# [Community Puzzle] Van Eck's sequence

For everyone who has faced troubles passing the final testcase. Note that printing to console is pretty heavy operation (this includes debug console messages).

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Exactly, I didnāt pass the last with console.error but without that it passed almost instantly. I used javascript map btw.

I think this can be a very good exercices to practice in C.

Hmm, my code is probably about the same then.
But the last test still takes over 10 sec.

Iām doing it in Bash. The only thing I store is the last known position of all elements, and the previous element.

Hello everyone, I have got a problem with my code : I donāt see how to maxsimize my code :

nb = int(input());n = int(input());ls = [];tour_final = 0
if nb < 201 and n < 1000001 :
while True and tour_final < n :
ls.append(str(nb)) #On ajoute
a = list.copy(ls);del a[-1]
if str(nb) not in a :
nb = 0
else :
t = -2
i = True
while i :
if str(ls[t]) == str(nb) :
i = False
nb = t*-1-1
t-=1
tour_final += 1
print(ls[-1])
Thankās, BiMathAx

I donāt get the example:

Term 1: The first term is 0.
Term 2: Since we havenāt seen 0 before, the second term is 0.

But we have seen 0 before, namely Term 1

The ābeforeā refers to term 1: You create the first term and in the same step you check if you have already seen the created number before.

Whenever I see the handle Crypticsy, I raise the difficulty level by one in my mind.
This is so hard!