Problem 5: Plus Minus

strip() - 刪除 string 字串末尾的指定字元（預設為空格）
format - print(format(0.5,”.6f”)) –> 0.500000

Problem 7: Mini-Max Sum

format - print(“{:d} {:d}”.format(MIN,MAX))

Problem 16: Divisible Sum Pairs

def divisibleSumPairs(n, k, ar):
    m=0
    for i in ar:
        ar2=ar.copy()
        for
 
 j in ar2.remove(i):
            if (i+j)\%k==0:
                m+=1
    return m

為什麼不對？ 報錯資訊是：   for j in ar2.remove(i):TypeError: 'NoneType' object is not iterable

ar2.remove(i) 這個操作的返回值是None

def divisibleSumPairs(n, k, ar):
    count = 0
    for i in range(n-1):
        for j in range(i+1,n):
            if
 
 0 == (ar[i] + ar[j]) % k:
                count += 1
    return count

Problem 26: Picking Numbers

• map(f,list): list 中每個元素都輸入到f得到結果；
• reduce(f,list): list前兩個元素
• from collections import Counter：
  a = Counter([1,2,3,1]) –> a[1] = 2

Problem 27: Climbing the Leaderboard

def climbingLeaderboard
 
(scores, alice):
    scores = list(set(scores))
    scores.sort(reverse = True)
    l = len(scores)
    rank = []
    for a in alice:
        while (l > 0) and (a >= scores[l-1]):
            l -= 1
        rank.append(l+1)
    return rank

Problem 28: The Hurdle Race

def hurdleRace(k, height):
    maxhurdle = max(height)
    if k >= maxhurdle:
        return 0
    else:
        return maxhurdle - k

Problem 29: Designer PDF Viewer

def designerPdfViewer(h, word):
    alpha = 'abcdefghijklmnopqrstuvwxyz'
    maxheight = 0
    for w in word:
        height = h[alpha.index(w)] 
        if height > maxheight:
            maxheight = height
    return maxheight * len(word)

Problem 30: Utopian Tree

def utopianTree(n):
    height = 1
    for i in range(1,n+1):
        # if i % 2 == 0:
        #     height = height + 1
        # else:
        #     height = height * 2
        height = height + 1 if i % 2 == 0 else height * 2
    return height

Problem 31:

return 'YES' if len([x for x in a if x <= 0]) < k else 'NO'

Problem 32:Beautiful Days at the Movies

def beautifulDays(i, j, k):
    count = 0
    for num in range(i,j+1):
        if 0 == abs(num-int(str(num)[::-1])) % k:
            count += 1
    return count

Problem 33:Viral Advertising

def viralAdvertising(n):
    shared = 5
    plike = 2
    for i in range(2,n+1):
        shared = math.floor(shared / 2) * 3
        plike += math.floor(shared / 2)
    return plike

Problem 34:Save the Prisoner!

    return s + m % n - 1

這個為啥不行？？？

Problem 35: Circular Array Rotation

def circularArrayRotation(a, k, queries):
    for i in queries:
        yield (a[(i-k)%n])

Problem 36: Sequence Equation

def permutationEquation(p):
    for i in range(len(p)):
        yield p.index(p.index(i+1) + 1) + 1

Problem 37: Jumping on the Clouds: Revisited