題目地址:
https://leetcode.com/problems/remove-vowels-from-a-string/
給定一個字符串,去掉其所有元音字母后返回。代碼如下:
import java.util.HashSet;
import java.util.Set;
public class Solution {
public String removeVowels(String S) {
if (S == null || S.isEmpty()) {
return S;
}
Set<Character> set = new HashSet<>();
set.add('a');
set.add('e');
set.add('i');
set.add('o');
set.add('u');
StringBuilder sb = new StringBuilder();
for (int i = 0; i < S.length(); i++) {
char c = S.charAt(i);
if (!set.contains(c)) {
sb.append(c);
}
}
return sb.toString();
}
}
時空複雜度。