预测球队比赛成绩

羽毛球比赛规则：

1、21分制，一场3局比赛，3局2胜

2、每球得分制

3、每回合中，取胜的一方加1分

4、当双方均为20分时，领先对方2分的一方赢得该局比赛

5、当双方均为29分时，先取得30分的一方赢得该局比赛

from random import random
def printIntro():
    print("29号羽毛球比赛(3局2胜)分析")
    print("这个程序模拟两个选手A和B的某种竞技比赛")
    print("程序运行需要A和B的能力值（以0到1之间的小数表示）")
def getInputs():
    a = eval(input("请输入选手A的能力值(0-1): "))
    b = eval(input("请输入选手B的能力值(0-1): "))
    n = eval(input("模拟比赛的场次: "))
    return a, b, n
def simNGames(n, probA, probB):
    sumA, sumB = 0, 0
    for i in range(n):
        winsA, winsB = 0, 0
        for j in range(3):
            scoreA, scoreB = simOneGame(probA, probB)
            if scoreA > scoreB:
                winsA += 1
            else:
                winsB += 1
            if winsA==2:
                break
            elif winsB==2:
                break
        if winsA==2:
            sumA+=1
        elif winsB==2:
            sumB+=1
    return sumA, sumB
def gameOver1(a,b):
    return a==21 or b==21 
def gameOver2(a,b):
    return abs(a-b)==2 or (a==b==29)    
def simOneGame(probA, probB):
    scoreA, scoreB = 0, 0
    serving = "A"
    while not gameOver1(scoreA, scoreB):
        if scoreA==20 and scoreB==20:#双方都为20分
            scoreA,scoreB=simOneGame1(probA,probB,serving)
            return scoreA,scoreB
        elif serving == "A":
            if random() < probA:
                scoreA += 1
            else:
                serving="B"
        else:
            if random() < probB:
                scoreB += 1
            else:
                serving="A"
    return scoreA, scoreB
def simOneGame1(probA,probB,serving):
    scoreA,scoreB = 20,20
    while not gameOver2(scoreA, scoreB):
        if serving == "A":
            if random() < probA:
                scoreA += 1
            else:
                serving="B"
        else:
            if random() < probB:
                scoreB += 1
            else:
                serving="A"
    if scoreA==29 and scoreB==29:#双方均为29分
        if serving == "A":
            if random() < probA:
                scoreA += 1
            else:
                serving="B"
        else:
            if random() < probB:
                scoreB += 1
            else:
                serving="A"
    return  scoreA, scoreB  
def printSummary(sumA, sumB):
    n = sumA + sumB
    print("竞技分析开始，共模拟{}场比赛".format(n))
    print("选手A获胜{}场比赛，占比{:0.1%}".format(sumA, sumA/n))
    print("选手B获胜{}场比赛，占比{:0.1%}".format(sumB, sumB/n))
def main():
    printIntro()
    probA, probB, n = getInputs()
    sumA, sumB = simNGames(n, probA, probB)
    printSummary(sumA, sumB)
main()