Same Code Slower In Python3 As Compared To Python2

I coded this problem at CodeChef and submitted it as Python3 solution: import sys n,k = map(int,sys.stdin.readline().split(' ')) nos = map(int,sys.stdin.readlines()) ans = 0 for i

Solution 1:

I can confirm that exactly the same solution passes the tests on python 2.7, but it timeouts on python 3.1:

import sys
try:
    from future_builtins importmap# enable lazy map on Python 2.7except ImportError:
    pass 

file = sys.stdin
n, k = map(int, next(file).split())
print(sum(1for i inmap(int, file) if i % k == 0))

file is an iterator over lines. The code supports large files due to map is lazy (doesn't consume the whole file at once).

The following code passes the tests on python 3.1:

import sys
n, k, *numbers = map(int, sys.stdin.buffer.read().split())
print(sum(1for i in numbers if i % k == 0))

Note: it doesn't support arbitrary large inputs (as well as your code in the question).

Solution 2:

In python3, things like map, zip return generators instead of a list. I think the generator brings the overhead that make your code TLE. To make a real list, use list comprehension [int(line) for line in std.sys]

Solution 3:

The error occurs the line that says, n,k = map(int,sys.stdin.readline().split(" ")). I tried to separate the n and the k, but it still seems to get stuck as soon as the map command is called. Here is a page that explains the map function: http://docs.python.org/2/library/functions.html#map Something seems strange with the syntax that neither I or IDLE could find. Hope this helps