leetcode-algorithms/src/FindCommonCharacters.java at master · anishLearnsToCode/leetcode-algorithms · GitHub

38 lines (35 loc) · 1.38 KB

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

public class FindCommonCharacters {

public List<String> commonChars(String[] words) {

Map<Character, Integer> commonChars = getCharsFrequency(words[0]);

Map<Character, Integer> wordChars;

for (int i = 1 ; i < words.length ; i++) {

wordChars = getCharsFrequency(words[i]);

for (char letter : commonChars.keySet()) {

commonChars.put(letter, Math.min(commonChars.get(letter), wordChars.getOrDefault(letter, 0)));

}

return toList(commonChars);

}

private List<String> toList(Map<Character, Integer> characters) {

List<String> result = new ArrayList<>();

for (Map.Entry<Character, Integer> entry : characters.entrySet()) {

if (entry.getValue() > 0) {

for (int i = 0 ; i < entry.getValue() ; i++) result.add(entry.getKey() + "");

}

return result;

}

private Map<Character, Integer> getCharsFrequency(String string) {

Map<Character, Integer> result = new HashMap<>();

char character;

for (int index = 0 ; index < string.length() ; index++) {

character = string.charAt(index);

result.put(character, result.getOrDefault(character, 0) + 1);

}

return result;

}

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