把一个骰子扔n次, n次朝上一面的点数和为s。 输入n, 打印出s的所有可能的值出现的概率。

Posted 2020-09-21

#一、
# 1.计算所有数之和
import datetime
start=datetime.datetime.now()
n=10
c=[]
a = [1,2,3,4,5,6]
b = [1,2,3,4,5,6]
total=len(a)**(n)
while n>1:
    for i in a:
        for j in b:
            c.append(i+j)
    b=c[:]
    c.clear()
    n-=1
print(b)
#2.计算各和的概率
sum=0
for i in set(b):
    print(‘和为%s的概率：‘%i,b.count(i)/total)
    sum+=b.count(i)/total
print(‘总的概率为：‘,sum)
end=datetime.datetime.now()
print((end-start).seconds)


#二、
import datetime
from decimal import Decimal
start=datetime.datetime.now()
def get_dice():
    # 一个骰子扔n次
    times = 10
    # 默认点数
    number = [1, 2, 3, 4, 5, 6]
    result = []
    dice = {}
    while times > 0:
        result.append(number)
        times -= 1

    length = len(result)
    # 所有可能性
    total = len(number) ** length

    if length >= 2:
        while length > 2:
            temp = []
            for i in result[-1]:
                for j in result[-2]:
                    temp.append(i+j)
            result.pop(-1)
            result[-1] = temp
            length -= 1

        for m in result[0]:
            for n in result[1]:
                dice[m+n] = dice.setdefault(m+n, 0) + 1
    else:
        for i in result[0]:
            dice[i] = 1

    for num, count in dice.items():
        dice[num] = str(Decimal(100.0*count/total).quantize(Decimal(‘0.000‘))) + ‘%‘
    return dice

for k, v in get_dice().items():
    print (k, v)

end=datetime.datetime.now()
print((end-start).seconds)