2506 - Count Pairs Of Similar Strings\.

Easy

You are given a 0-indexed string array words.

Two strings are similar if they consist of the same characters.

• For example, "abca" and "cba" are similar since both consist of characters 'a', 'b', and 'c'.

• However, "abacba" and "bcfd" are not similar since they do not consist of the same characters.

Return the number of pairs (i, j) such that 0 <= i < j <= word.length - 1 and the two strings words[i] and words[j] are similar.

Example 1:

Input: words = "aba","aabb","abcd","bac","aabc"

Output: 2

Explanation: There are 2 pairs that satisfy the conditions:

• i = 0 and j = 1 : both words0 and words1 only consist of characters 'a' and 'b'.

• i = 3 and j = 4 : both words3 and words4 only consist of characters 'a', 'b', and 'c'.

Example 2:

Input: words = "aabb","ab","ba"

Output: 3

Explanation: There are 3 pairs that satisfy the conditions:

• i = 0 and j = 1 : both words0 and words1 only consist of characters 'a' and 'b'.

• i = 0 and j = 2 : both words0 and words2 only consist of characters 'a' and 'b'.

• i = 1 and j = 2 : both words1 and words2 only consist of characters 'a' and 'b'.

Example 3:

Input: words = "nba","cba","dba"

Output: 0

Explanation: Since there does not exist any pair that satisfies the conditions, we return 0.

Constraints:

• 1 <= words.length <= 100

• 1 <= words[i].length <= 100

• words[i] consist of only lowercase English letters.