import random
import xlwt

wins=0
attempts=500000

book=xlwt.Workbook(encoding="utf-8")
sheet1=book.add_sheet("Results")
sheet1.write(0, 0, "p")
sheet1.write(0, 1, "wins")
sheet1.write(0, 2, "attempts")
i=1

while (p<=1):
    wins=0
    sheet1.write(i, 0, p)
    for case in range(0, attempts):
        score=0
        for flip in range(0, 100):
            a_expectancy=(99-flip)*(2*p-1)

            result=0
            toss=random.uniform(0,1)
            if (score+a_expectancy>=0):
                #go for coin A
                if (toss>=p): #tails
                    result=-1
                else: #heads
                    result=1

            else:
                #go for coin B
                if (toss>=0.5):
                    result=2
                else:
                    result=-2

            score+=result

        if (score>0):
            wins+=1
    sheet1.write(i, 1, wins)
    sheet1.write(i, 2, attempts)
    i+=1;
    p+=0.05
book.save("results.xls")