Perl, Python, Erlang, C语言运行速度的比较
作者:互联网
主要是通过 蒙特卡罗法来计算圆周率。代码如下:
1) pi.pl:
$time1 = time(); foreach (1..20000000) { my($x, $y) = (rand(), rand()); if(sqrt($x ** 2 + $y ** 2) < 1) { $total += 1; } } $pi = 4.0 * $total / 20000000; $time2 = time(); print "Pi = " , $pi, " time = ", $time2 - $time1;
Perl脚本运行结果如下,2千万次平均执行时间是27秒左右:
2)pi.py
import random import datetime import math starttime = datetime.datetime.now() total = 0 for i in xrange(20000000): x, y = random.random(), random.random() if math.sqrt(x ** 2 + y ** 2) < 1: total += 1 pi = 4.0 * total / 20000000 endtime = datetime.datetime.now() print "pi = ", pi , " time = ", (endtime - starttime).seconds
Python运行结果如下,2千万次平均执行时间是30秒左右:
3) pi.erl
-module(pi). -export([pi/1]). pi(N) -> pi(N, N, 0). pi(N, 0, Total) -> 4.0 * Total / N; pi(N, I, Total) -> X = random:uniform(), Y = random:uniform(), R = math:sqrt(X * X + Y * Y), if R < 1 -> pi(N, I - 1, Total + 1); true -> pi(N, I - 1, Total) end.
Erlang运行如下,2千万次平均执行时间是30秒左右:
4) pi.c
#include#include#include#includeint main() { time_t start_time, end_time; double elapsed_time; double x, y, pi; long i , total; total = 0; srand((unsigned)time(0)); time(&start_time); for(i = 0 ; i < 20000000; i ++ ) { x = rand() / (double)(RAND_MAX); y = rand() / (double)(RAND_MAX); if (sqrt(x * x + y * y) < 1) { total += 1; } } pi = 4.0 * total / 20000000; time(&end_time); elapsed_time = difftime(end_time, start_time); printf(" total = %d, pi = %f, time = %f", total ,pi, elapsed_time); }
C运行如下, 2千万次平均执行时间是3秒左右:
Python, Erlang 速度相当, Perl稍微快一丁点, C语言是它们的10倍。
标签:秒左右,Erlang,Python,random,C语言,千万次,time,pi,Total 来源: https://blog.51cto.com/huanghongqiao/2746814