LeetCode 2531. Make Number of Distinct Characters Equal

You are given two 0-indexed strings word1 and word2.

A move consists of choosing two indices i and j such that 0 <= i < word1.length and 0 <= j < word2.length and swapping word1[i] with word2[j].

Return true if it is possible to get the number of distinct characters in word1 and word2 to be equal with exactly one move. Return false otherwise.

Example 1:

Input: word1 = "ac", word2 = "b"

Output: false

Explanation: Any pair of swaps would yield two distinct characters in the first string, and one in the second string.

Example 2:

Input: word1 = "abcc", word2 = "aab"

Output: true

Explanation: We swap index 2 of the first string with index 0 of the second string. The resulting strings are word1 = "abac" and word2 = "cab", which both have 3 distinct characters.

Example 3:

Input: word1 = "abcde", word2 = "fghij"

Output: true

Explanation: Both resulting strings will have 5 distinct characters, regardless of which indices we swap.

Constraints:

• 1 <= word1.length, word2.length <= 105

• word1 and word2 consist of only lowercase English letters.

一开始想到的是用hashmap，然而。。。还是直接用数组快啊，毕竟就是常数的复杂度。

Runtime: 11 ms, faster than 67.88% of Java online submissions for Make Number of Distinct Characters Equal.

Memory Usage: 43.5 MB, less than 64.25% of Java online submissions for Make Number of Distinct Characters Equal.