Today when I am trying to solve acmsguru-113 with PyPy3 (because when I was submitting Python3, CodeForces noticed me that "Almost always, if you send a solution on PyPy, it works much faster"), I got lots of Wrong Answer on test 1. I thought it impossible because it's actually a very simple problem and I have confidence in my code. Then I rewrite it in C++, and with identical implementation it's accepted.
Then I realized that there may be problems in input format, so I wrote a tokenizer to solve this problem. However, it's just another WA on 1.
After one hour of struggling in finding bugs and differences, I found nothing but submitted it with Python3 — and it was an accepted!
Here are the python code with tokenizer, and submissions with this code : (It's not allow to view others' submissions so I paste here)
63721667 Oct/29/2019 19:32UTC+8 Lily 113 — Nearly prime numbers Python 3 Accepted 186 ms 0 KB
63721403 Oct/29/2019 19:28UTC+8 Lily 113 — Nearly prime numbers PyPy 3 Wrong answer on test 1 124 ms 0 KB
now_token = input().split()
now_token.reverse()
def nxt_token():
global now_token
if len(now_token) > 0:
ret = now_token[-1]
now_token.pop()
return ret
else:
now_token = input().split()
now_token.reverse()
return nxt_token();
n = int(nxt_token())
while n > 0:
n -= 1
x = int(nxt_token())
ans = False
i = 2
while i * i <= x:
if x % i == 0:
y = x // i
ans = (y > 1)
j = 2
while j * j <= y:
if y % j == 0:
ans = 0
break
j += 1
break
i += 1
if ans:
print("Yes")
else:
print("No")
I found it true that the data is not corresponding to the input format by asserting, but there must be something else with the PyPy3 interpreter.
Could anybody help me find the reason of it? Thanks a lot. QAQ
UPD: MikeMirzayanov has fixed the issue by updating PyPy. The issue is caused by older versions of PyPy output '\n' instead of '\r\n' on Windows.
Auto comment: topic has been updated by -14 (previous revision, new revision, compare).
I reported a while back that PyPy3 doesn't print with \r on windows, which is what I'm suspecting causes the WA. I first noticed this issue when hacks on cf mysteriously failed with PyPy3 but not Cpython3. Unfortunately I think cf uses the version of PyPy3 just before the fix was added.
Just tried using PyPy3 and manually end each print with \r\n and that gets AC. So the issue is that cf's version of PyPy3 only uses \n and not \r\n.
I've updated PyPy to the latest version 7.2.0
Thanks a lot!
Nice
Auto comment: topic has been updated by -14 (previous revision, new revision, compare).