使用python已知平均数求随机数

时间：2021-12-18 14:44:21

问题描述：产生40个数，范围是363-429之间，平均值为402

思路：

1 产生一个随机数

2 使用平均数减去随机数求出第二个数，生成20组

3 将排序打乱

# -*- coding: cp936 -*-

import random

import string

###################产生随机整数###################

###################第一个数随机产生，第二个使用平均数求出###################

#count 数字的个数

#average 平均数

#begin 起始区间

#end 结束区间

def int_random (count, average, begin, end):

    #print "wzh_random"

    numarr = [0 for x in range(2)];

    i = 0;

    while (1):

      num_first = random.randrange(begin, end);

      #第二个数

      num_second = average * 2 - num_first;

      if (num_second >= begin and num_second <= end):

          numarr[i] = num_first;

          i = i + 1;

          numarr[i] = num_second;

          break

    return numarr;

###################产生随机数###################

###################第一个数随机产生，第二个使用平均数求出###################

#count 数字的个数

#average 平均数

#begin 起始区间

#end 结束区间

def float_random (count, average, begin, end):

    #print "wzh_random"

    numarr = [0 for x in range(2)];

    i = 0;

    while (1):

      num = random.uniform(begin, end);

      #取两位小数

      num_first = round(num, 2);

      #第二个数

      num_second = average * 2 - num_first;

      if (num_second >= begin and num_second <= end):

          numarr[i] = num_first;

          i = i + 1;

          numarr[i] = num_second;

          break

    return numarr;

###################写文件###################

def write_file (filename, content):

    fo = open (filename, "ab");

    fo.write(content);

    fo.close();

def show_list (list):

    for i in list:

        print i,

    print;

###################主函数调用产生整形随机数###################

#40个数字，平均数400，363 - 429 之间

def test_random_int():

    count = 40;

    average = 402;

    begin = 363;

    end = 429;

    numarr_count = 0;

    numarr = [0 for x in range(count)];

    for i in range (count / 2):

        list = int_random (40, 402, 363, 429)

        j = 0;

        for j in range (len(list)):

             numarr[numarr_count] = list[j];

             numarr_count += 1;

    content = '';

    #打乱排序

    print "数据未打乱：";

    show_list (numarr)

    random.shuffle(numarr);

    print "数据打乱：";

    show_list (numarr)

    for i in numarr:

        content = content + ' ' + str(i);

    #print content;

    #追加写入文件

    filename = "test.txt";

    print "文件名称：",filename;

    write_file (filename, content)

    write_file (filename, "\n");

###################主函数调用产生实型随机数###################

#40个数字，平均数400，363 - 429 之间

def test_random_float():

    count = 40;

    average = 402;

    begin = 363;

    end = 429;

    numarr_count = 0;

    numarr = [0 for x in range(count)];

    for i in range (count / 2):

        list = float_random (40, 402, 363, 429)

        j = 0;

        for j in range (len(list)):

             numarr[numarr_count] = list[j];

             numarr_count += 1;

    content = '';

    #打乱排序

    print "数据未打乱：";

    show_list (numarr)

    random.shuffle(numarr);

    print "数据打乱：";

    show_list (numarr)

    for i in numarr:

        content = content + ' ' + str(i);

    #print content;

    #追加写入文件

    filename = "test.txt";

    print "文件名称：",filename;

    write_file (filename, content)

    write_file (filename, "\n");

#调用测试产生整形随机数

test_random_int();

#调用测试产生实型随机数

test_random_float();

相关文章