Problem of the Day
A new programming or logic puzzle every Mon-Fri

String Rotation

Given a string s1 and a string s2, write a function to return whether s2 is a rotation of s1 using only one call to strstr (or a similar function)? For example:

is_rotation(ABCD, CDAB) //return  true

is_rotation(ABCD, ACBD) //return false

Permalink: http://problemotd.com/problem/string-rotation/

Comments:

  • Anonymous - 9 years, 10 months ago

    I think I got it. Python 3

    def is_rotated(first, second):
    if len(first) != len(second):
        return False
    try:
        start = first.index(second[0])
    except ValueError:
        return False
    for i in range(start,  start + len(first)):
        if first[i % len(first)] != second[i-start]:
            return False
    return True

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  • Byron Mayne - 9 years, 9 months ago

    def is_rotation( value1, value2 ):
    if len(value1) != len(value2):
        return False

    length = len(value1) 

    for x in range(0, length):
        if value1[x] != value2[length - x - 1]:
            return false

    return True


print(is_rotation("ABBC", "CBA"))
print(is_rotation("ABC", "CBA"))

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