Given a string, find the rank of the string amongst its permutations sorted lexicographically.
Example 1:
Input:
S = "abc"
Output:
1
Explanation:
The order permutations with letters
'a', 'c', and 'b' :
abc
acb
bac
bca
cab
cba
Example 2:
Input:
S = "acb"
Output:
2
Your Task:
You don't need to read input or print anything. Your task is to complete the function findRank() which takes the string S as input parameter and returns the rank of the string amongst its permutations.
It is guaranteed no characters are repeated in the string.
Expected Time Complexity: O(|S|*26)
Expected Auxiliary Space: O(|S|)
Note: |S| represents the length of string S.
Constraints:
1 ≤ |S| ≤ 18

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