README_EN.md

1941. Check if All Characters Have Equal Number of Occurrences

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Description

Given a string s, return true if s is a good string, or false otherwise.

A string s is good if all the characters that appear in s have the same number of occurrences (i.e., the same frequency).

 

Example 1:

Input: s = "abacbc"
Output: true
Explanation: The characters that appear in s are 'a', 'b', and 'c'. All characters occur 2 times in s.

Example 2:

Input: s = "aaabb"
Output: false
Explanation: The characters that appear in s are 'a' and 'b'.
'a' occurs 3 times while 'b' occurs 2 times, which is not the same number of times.

 

Constraints:

• 1 <= s.length <= 1000
• s consists of lowercase English letters.

Solutions

Python3

class Solution:
    def areOccurrencesEqual(self, s: str) -> bool:
        counter = Counter(s)
        cnt = -1
        for c, times in counter.items():
            if cnt == -1:
                cnt = times
            elif cnt != times:
                return False
        return True

Java

class Solution {
    public boolean areOccurrencesEqual(String s) {
        int[] counter = new int[26];
        for (char c : s.toCharArray()) {
            ++counter[c - 'a'];
        }
        int cnt = -1;
        for (int i = 0; i < 26; ++i) {
            if (counter[i] == 0) {
                continue;
            }

            if (cnt == -1) {
                cnt = counter[i];
            } else if (cnt != counter[i]) {
                return false;
            }
        }
        return true;
    }
}

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