Harvard CS50 学习笔记（六）

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print("Hello, World")

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answer = get_string("What is your name?")
print("Hello, " + answer)

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answer = get_string("What is your name?")
print(f"Hello,  {answer}")

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count += 1

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if x < y:
    print("x is less than y")
elif x > y:
    print("x is greater than y")
else:
    print("x is equal to y")

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while True:
    print("hello, world")

i = 0
while i < 3:
    print("hello, world")
    i += 1
    
for i in [0, 1, 2]:
    print("hello, world")

for i in range(3):
    print("hello, world")

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import cs50
from cs50 import get_float
from cs50 import get_int
from cs50 import get_string
from cs50 import get_float, get_int, get_string

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from cs50 import get_int

x = get_int("x: ")
y = get_int("y: ")

# 此结果为float，解决数值丢失问题
z = x / y
print(z)

# 此结果为int，放弃精度部分
z = x // y
print(z)

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try:
    x = int(input(x: ))
except: 
  	print("That is not an int! ")
    exit()
    
try:
    y = int(input(y: ))
except ValueError: 
  	print("That is not an int! ")
    exit()
    
print(x + y)

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from cs50 import get_int

x = get_int("x: ")
y = get_int("y: ")

z = x / y
# 精确到小数点后50位，浮点型精度问题仍然存在
print(f"{z:.50f}")

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def loop(int n): 
  	for i in range(n):
      	print(n)
    return n

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def get_height():
  	while True:
      	n = get_int("Height: ")
        if n > 0:
          	break
    return n

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from cs50 import get_int

scores = []
for i in range(3):
  	score = get_int("Score: ")
    # 添加元素
    # scores.append(score)
    scores += [score]
    
average = sum(scores) / len(scores)
print(f"Average: {average}")

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from cs50 import get_string

before = get_string("Before: ")
print("After: ", end="")
for c in before:
  	print(c.upper(), end="")
print()

after = before.upper()
print(f"After, {after}")

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# Simulate a sports tournament

import csv
import sys
import random

# Number of simluations to run
N = 1000


def main():

    # Ensure correct usage
    if len(sys.argv) != 2:
        sys.exit("Usage: python tournament.py FILENAME")

    teams = []
    with open(sys.argv[1], "r") as file:
        reader = csv.DictReader(file)
        for row in reader:
            row["rating"] = int(row["rating"])
            teams.append(row)


    counts = {}
    for team in teams:
        counts[team["team"]] = 0

    for i in range(N):
        name = simulate_tournament(teams)
        counts[name] += 1

    # Print each team's chances of winning, according to simulation
    for team in sorted(counts, key=lambda team: counts[team], reverse=True):
        print(f"{team}: {counts[team] * 100 / N:.1f}% chance of winning")


def simulate_game(team1, team2):
    """Simulate a game. Return True if team1 wins, False otherwise."""
    rating1 = team1["rating"]
    rating2 = team2["rating"]
    probability = 1 / (1 + 10 ** ((rating2 - rating1) / 600))
    return random.random() < probability


def simulate_round(teams):
    """Simulate a round. Return a list of winning teams."""
    winners = []

    # Simulate games for all pairs of teams
    for i in range(0, len(teams), 2):
        if simulate_game(teams[i], teams[i + 1]):
            winners.append(teams[i])
        else:
            winners.append(teams[i + 1])

    return winners


def simulate_tournament(teams):
    """Simulate a tournament. Return name of winning team."""
    while len(teams) != 1:
        teams = simulate_round(teams)
    return teams[0]["team"]

if __name__ == "__main__":
    main()

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from cs50 import get_string

name = get_string("What is your name?\n")
print(f"hello, {name}")

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from cs50 import get_int

while True:
    height = get_int("Height: ")

    if height < 1 or height > 8:
        continue
    else:
        for i in range(height):
            for j in range(height - i - 1):
                print(" ", end="")
            for k in range(i + 1):
                print("#", end="")
            print("  ", end="")
            for m in range(i + 1):
                print("#", end="")
            print()
        break

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from cs50 import get_int, get_string


americanExpressLength = 15
masterCardLength = 16
visaLength = 13

americanExpressStarts = [34, 37]
masterCardStarts = [51, 52, 53, 54, 55]
visaStart = 4


def main():
    number = get_string("Number: ")
		# 把号码依次变成数字存到数组
    numbers = [int(c) for c in number]
    count = len(numbers)
    # 开头两位数
    starts = int(str(numbers[0]) + str(numbers[1]))

    valid = validate(numbers)

    if not valid:
        print("INVALID\n")
        exit(1)

    if isAmericanExpress(count, starts):
        print("AMEX\n")
        exit(0)
    elif isMasterCard(count, starts):
        print("MASTERCARD\n")
        exit(0)
    elif isVisa(count, starts, numbers):
        print("VISA\n")
        exit(0)
    else:
        print("INVALID\n")
        exit(1)

# 验证号码是否正确
def validate(numbers):
    nums = [];
    for num in range(len(numbers) - 2, -1, -2):
        i = numbers[num] * 2
        if i < 10:
            nums.append(i)
        else:
            tmp = str(i)
            nums.append(int(tmp[0]))
            nums.append(int(tmp[1]))
    total = sum(nums)
    for num in range(len(numbers) - 1, -1, -2):
        total += numbers[num]
    if int(str(total)[-1]) == 0:
        return True
    else:
        return False


def isAmericanExpress(count, starts):
    return count == americanExpressLength and starts in americanExpressStarts

def isMasterCard(count, starts):
    return count == masterCardLength and starts in masterCardStarts

def isVisa(count, starts, numbers):
    if count == masterCardLength or count == visaLength:
        if numbers[0] == visaStart:
            return True
    return False

if __name__ == "__main__":
    main()

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from cs50 import get_string

text = get_string("Text: ")

letterCount = 0
wordCount = 1
sentenceCount = 0

for c in text:
    if (c >= 'a' and c <= 'z'):
        letterCount += 1
    if (c >= 'A' and c <= 'Z'):
        letterCount += 1
    elif c == ' ':
        wordCount += 1
    elif c == '.' or c == '!' or c == '?':
        sentenceCount += 1

L = letterCount * 100 / wordCount
S = sentenceCount * 100 / wordCount
index = round(0.0588 * L - 0.296 * S - 15.8)

if index < 1:
    print("Before Grade 1")
elif index >= 16:
    print("Grade 16+")
else:
    print("Grade " + str(index))

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import csv
import sys

def main():
    # Ensure correct usage
    if len(sys.argv) != 3:
        sys.exit("Usage: python dna.py data.csv sequence.txt")

    people = []
    genes = []

    # 读文件头
    with open(sys.argv[1], "r") as file:
        reader = csv.reader(file)
        for row in reader:
            for i in range(len(row)):
                if (i + 1) == len(row):
                    break
                genes.append(row[i + 1])
            break

    # 读文件为dict数组
    with open(sys.argv[1], "r") as file:
        reader = csv.DictReader(file)
        for row in reader:
            people.append(row)

    # 读DNA序列
    sequence = open(sys.argv[2]).read()

    # DNA序列连续出现次数最多的数组
    counts = genesCount(sequence, genes)

    # 比较
    result = getResult(counts, people, genes)

    print(result)

# 获取DNA序列连续出现次数最多的数组
def genesCount(sequence, genes):
    counts = []
    for gene in genes:
        total = 0
        tmp = [0]
        for i in range(len(sequence)):
            currentGene = sequence[i:len(gene) + i]
            if currentGene == gene:
                nextGene = sequence[(i + len(gene)):(i + len(gene) + len(gene))]
                if nextGene == gene:
                    total += 1
                    i += len(gene)
                else:
                    tmp.append(total)
                    total = 0
        temp = tmp
        counts.append(max(tmp) + 1)
    return counts

# 比较结果
def getResult(counts, people, genes):

    result = "No match"

    flag = True
    for person in people:
        for i in range(len(counts)):
            gene = genes[i]
            count = counts[i]
            if int(person[gene]) == count:
                flag = True
                continue
            else:
                flag = False
                break
        if flag:
            result = person["name"]
            break
    return result


if __name__ == "__main__":
    main()