Why is my computation so much faster in C# than Python

Question

Below is a simple piece of process coded in C# and Python respectively (for those of you curious about the process, it\'s the solution for Problem

Answer 1

First of all you need to change the algorithm to solve this problem:

#!/usr/bin/env python

import sys
from timeit import default_timer as timer

pyver = sys.version_info;

print(">")
print(">  Smallest multiple of 2 ... K");
print(">")
print(">  Python version, interpreter version: {0}.{1}.{2}-{3}-{4}".format(
    pyver.major, pyver.minor, pyver.micro, pyver.releaselevel, pyver.serial))
print(">")

K = 20;

print("  K = {0:d}".format(K))
print("")

t0 = timer()

N = K
NP1 = N + 1
N2 = (N >> 1) + 1
vec = range(0, NP1)
smalestMultiple = 1

for i in range(2, N2):
    divider = vec[i]
    if divider == 1:
        continue
    for j in range(i << 1, NP1, i):
        if (vec[j] % divider) == 0:
            vec[j] /= divider

for i in range(2, NP1):
    if vec[i] != 1:
        smalestMultiple = smalestMultiple * vec[i]

t1 = timer()

print("  smalest multiple = {0:d}".format(smalestMultiple))
print("  time elapsed = {0:f} sec.".format(t1 - t0))

Otput on Linux/Fedora 28/Intel(R) Core(TM) i7-2760QM CPU @ 2.40GHz:

>  Smallest multiple of 2 ... K
>
>  Python version, interpreter version: 2.7.15-final-0
>
>  K = 20
>
>  smalest multiple = 232792560
>  time elapsed = 0.000032 sec.