08 Permutation in a String (hard)

Given a string and a pattern, find out if the string contains any permutation of the pattern.

Permutation is defined as the re-arranging of the characters of the string. For example, “abc” has the following six permutations:

1. abc
2. acb
3. bac
4. bca
5. cab
6. cba

If a string has ‘n’ distinct characters, it will have n!n! permutations.

Example 1:

Input: String="oidbcaf", Pattern="abc"Output: trueExplanation: The string contains "bca" which is a permutation of the given pattern.

Example 2:

Input: String="odicf", Pattern="dc"Output: falseExplanation: No permutation of the pattern is present in the given string as a substring.

Example 3:

Input: String="bcdxabcdy", Pattern="bcdyabcdx"Output: trueExplanation: Both the string and the pattern are a permutation of each other.

Example 4:

Input: String="aaacb", Pattern="abc"Output: trueExplanation: The string contains "acb" which is a permutation of the given pattern.