反转字符串中的单词 III Reverse Words in a String III
题目
给定一个字符串，你需要反转字符串中每个单词的字符顺序，同时仍保留空格和单词的初始顺序
以下为详细说明： Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.
Example 1:
Input: "Let's take LeetCode contest"
Output: "s'teL ekat edoCteeL tsetnoc"
Note: In the string, each word is separated by single space and there will not be any extra space in the string.
思路&题解
public String reverseWords(String s) {
StringBuilder builder = new StringBuilder();
Stack<Character> stack = new Stack<>();
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == ' ') {
while (!stack.isEmpty()) {
builder.append(stack.pop());
}
builder.append(' ');
} else {
stack.push(s.charAt(i));
}
}
while (!stack.isEmpty()) {
builder.append(stack.pop());
}
return builder.toString();
}