PTA的Python练习题（六）

从 第3章-8 字符串逆序 开始

1.

n = str(input())
n1=n[::-1]
print(n1)

2.

不是很好做这道题，自己还是C语言的思维，网上几乎也找不到什么答案

s = input()
idx = s.find("#")
s = s[:idx]
ss = s[:idx]
s_16 = "0123456789ABCDEFabcdef"

for c in s:
    if c not in s_16:
        s = s.replace(c, '')

flag = 0
for c in ss:
    if c in s_16:
        flag = ss.find(c)
        break

if '-' in ss[:flag]:
    s = '-' + s

if len(s) == 0:
    num_10 = 0
else:
    num_10 = int(s, 16)
print(num_10)

3.

滤掉5个字母，还有空格和感叹号

a=input()
count=0
for i in range(0,len(a)):
    if(a[i]!='A' and a[i]!='E' and a[i]!='I' and a[i]!='O' and a[i]!='U' and a[i]!='!' and a[i]!=' ' and 'A'<=a[i]<='Z'):
        count=count+1
print(count)

4.

我还在思考字符串怎么排序，发现其实之前做过的sort()函数可以用来无差别排序，一下子就简单了：

ls =list(input().split())
ls1=sorted(ls)
print("After sorted")
for i in ls1:
    print(i)