题目
Write a function that takes a string as input and reverse only the vowels of a string.
Example 1:
Given s = “hello”, return “holle”.
Example 2:
Given s = “leetcode”, return “leotcede”.
Note:
The vowels does not include the letter “y”.
思路
用两个index 分别记录头和尾的位置，然后一一交换元音字母就好。
代码
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| bool judge(char a) {
switch(a) {
case 'a':
case 'e':
case 'i':
case 'o':
case 'u':
case 'A':
case 'E':
case 'I':
case 'O':
case 'U': return true;
default: return false;
}
}
string reverseVowels(string s) {
int start = 0, end = s.size()-1;
while(end>start) {
if(!judge(s[start])) {
start++;
}
else if(!judge(s[end])) {
end--;
}
else {
swap(s[start++],s[end--]);
}
}
return s;
}
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|
boolean judge(char a) {
switch(a) {
case 'a':
case 'e':
case 'i':
case 'o':
case 'u':
case 'A':
case 'E':
case 'I':
case 'O':
case 'U': return true;
default: return false;
}
}
public String reverseVowels(String s) {
int start = 0, end = s.length()-1;
char[] chars = s.toCharArray();
while(end>start) {
if(!judge(chars[start])) {
start++;
}
else if(!judge(chars[end])) {
end--;
}
else {
char temp = chars[start];
chars[start] = chars[end];
chars[end] = temp;
start++;
end--;
}
}
return new String(chars);
}
|