PTA的Python练习题（十五）

第4章-12 求满足条件的斐波那契数

a=eval(input())
b=c=1
d=1
for i in range(a):
    c=b
    b=d
    d=b+c
    if d>a:
        print('{}'.format(d))
        break

第4章-13 求误差小于输入值的e的近似值

a=eval(input())
b=1
count=1
count2=0
for i in range(1,100000):
    b=b*i
    count2=count
    count=count+1/b
    if (count-count2)<a:
        print('{:6f}'.format(count))
        break

第4章-14 统计字符

参考了别人的代码：

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s=[]
count=0;letters=0;space=0;digit=0;others=0
while True:
    b=list(input())
    count=count+1
    s.extend(b)
    if len(s)+count>10:
        count=count-1
        break
for c in s:
    if c.isalpha():
        letters+=1
    elif c.isspace():
        space+=1
    elif c.isdigit():
        digit+=1
    else:
        others+=1
print('letter = {}, blank = {}, digit = {}, other = {}'.format(letters,space+count,digit,others))

用列表输入，用count算回车数，如果合计大于10就退出循环，下面调用python自带函数计算