[PYTHON] TLE seemed to be scary depending on how the input was received

Yes. codeforces http://codeforces.com/contest/373/problem/C

Original tweet https://twitter.com/cocodrips/statuses/412848727175331840 Published Gist https://gist.github.com/cocodrips/8001370

Please refer to the above publication for the full text of the original code.

originally

if __name__ == "__main__":
    num = map(int, raw_input().split())
    num=num[0]
    data = []
    for _ in range(num):
        next=map(int, raw_input().split())
        data.append(next[0])
    solve(data)

my proposal

if __name__ == "__main__":
    num = int(raw_input())
    data = []
    for x in range(num):
        data.append(int(raw_input()))
    solve(data)

For the test data, copy the sample case and prepare 1 line + 200,000 lines of data. The first line is the number of lines to be given, and the subsequent 200,000 lines are the data copied to the texto.

Ichio's CPU and memory Processor 2.5 GHz Intel Core i5 Memory 16 GB 1333 MHz DDR3

Time measurement

time

import=time
start=time.clock()
##Other execution part
end=time.clock()
t=end-start

How you commented

if __name__ == "__main__":
    num = int(raw_input())
    data = (int(raw_input()) for _ in xrange(num))
    solve(data)

Run 3 times and list the middle value in the table below

Part 1: Original data Part 2: num = int (raw_input ()) Only the way to receive the first line is changed Part 3: Change only how to receive data.append (int (raw_input ())) while turning with for Part 4: Both changed Part 5: How you commented

The time difference was significant this time because of how to receive the second and subsequent lines ...

The test case in my first line was 200,000, and I received only 6 digits per line from 500000, which was the maximum TLE on the preconditions for the question, and I could not feel the time difference.

At first glance, it seems that there is not much difference between Part 3, 4 and Part 5, and it seems good to say that there is a difference in speed depending on whether or not it is less than 0.65 seconds.

As a bonus

data.append(input())

 When I removed the cast with int, it took several times longer, so it seems better not to remove it.