LeetCode 1647. Minimum Deletions to Make Character Frequencies U

A string s is called good if there are no two different characters in s that have the same frequency.

Given a string s, return the minimum number of characters you need to delete to make s good.

The frequency of a character in a string is the number of times it appears in the string. For example, in the string "aab", the frequency of 'a' is 2, while the frequency of 'b' is 1.

Example 1:

Input: s = "aab"

Output: 0

Explanation: s is already good.

Example 2:

Input: s = "aaabbbcc"

Output: 2

Explanation: 

You can delete two 'b's resulting in the good string "aaabcc". Another way it to delete one 'b' and one 'c' resulting in the good string "aaabbc".

Example 3:

Input: s = "ceabaacb"

Output: 2

Explanation: 

You can delete both 'c's resulting in the good string "eabaab". Note that we only care about characters that are still in the string at the end (i.e. frequency of 0 is ignored).

这里面的排序就有点没必要的，

我是依次遍历的，如果这个frequency出线过，那么就--，res++，同时还得大于0，不然还是过不了的。只是没想到能过了。。。

Runtime: 79 ms, faster than 12.40% of Java online submissions for Minimum Deletions to Make Character Frequencies Unique.

Memory Usage: 43.7 MB, less than 15.42% of Java online submissions for Minimum Deletions to Make Character Frequencies Unique.