problem set 1

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Counting Vowels

(10 points possible)

Assume s is a string of lower case characters.

Write a program that counts up the number of vowels contained in the string s. Valid vowels are:

'a', 'e', 'i', 'o', and 'u'. For example, if s = 'azcbobobegghakl', your program should print:

Number of vowels: 5

For problems such as these, do not include raw_input statements or define the variable s in any

way. Our automating testing will provide a value of s for you - so the code you submit in the

following box should assume s is already defined. If you are confused by this instruction, please

review L4 Problems 10 and 11 before you begin this problem set.

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# Paste your code into this box

Status: Unanswered

unsubmitted

Counting bobs



Write a program that prints the number of times the string 'bob' occurs in s. For example, if s =

'azcbobobegghakl', then your program should print

Number of times bob occurs is: 2





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Status: Unanswered

unsubmitted

Alphabetical Substrings



Write a program that prints the longest substring of s in which the letters occur in alphabetical

order. For example, if s = 'azcbobobegghakl', then your program should print

Longest substring in alphabetical order is: beggh

In the case of ties, print the first substring. For example, if s = 'abcbcd', then your program

should print

Longest substring in alphabetical order is: abc





Note: This problem is fairly challenging. We encourage you to work smart. If you've spent more

than a few hours on this problem, we suggest that you move on to a different part of the course.

If you have time, come back to this problem after you've had a break and cleared your head.

1


Status: Unanswered

unsubmitted

problem set 1

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