Given two strings, the task is to find if a string can be obtained by rotating another string two places.
Examples:
Input: string1 = “amazon”, string2 = “azonam”
Output: Yes
// rotated anti-clockwise
Input: string1 = “amazon”, string2 = “onamaz”
Output: Yes
// rotated clockwise
Asked in: Amazon Interview
1- There can be only two cases:
a) Clockwise rotated
b) Anti-clockwise rotated
2- If clockwise rotated that means elements
are shifted in right.
So, check if a substring[2.... len-1] of
string2 when concatenated with substring[0,1]
of string2 is equal to string1. Then, return true.
3- Else, check if it is rotated anti-clockwise
that means elements are shifted to left.
So, check if concatenation of substring[len-2, len-1]
with substring[0....len-3] makes it equals to
string1. Then return true.
4- Else, return false.
Below is the implementation of the above approach.
Javascript
<script>// Javascript program to check if a// string is two time rotation of // another string. // Method to check if string2 is // obtained by string 1function isRotated(str1, str2){ if (str1.length != str2.length) return false; if (str1.length < 2) { return str1.localeCompare(str2); } let clock_rot = ""; let anticlock_rot = ""; let len = str2.length; // Initialize string as anti-clockwise // rotation anticlock_rot = anticlock_rot + str2.substring(len - 2, len + 1) + str2.substring(0, len - 1) ; // Initialize string as clock wise rotation clock_rot = clock_rot + str2.substring(2, str2.length - 2 + 1) + str2.substring(0, 2 + 1); // Check if any of them is equal // to string1 return (str1.localeCompare(clock_rot) || str1.localeCompare(anticlock_rot));}// Driver codelet str1 = "neveropen";let str2 = "eksge";document.write(isRotated(str1, str2) ? "Yes" : "No");// This code is contributed by rag2127</script> |
Output:
Yes
Time Complexity: O(n), where n is the size of the given string.
Please refer complete article on Check if a string can be obtained by rotating another string 2 places for more details!
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