题目描述
牛客最近来了一个新员工Fish,每天早晨总是会拿着一本英文杂志,写些句子在本子上。同事Cat对Fish写的内容颇感兴趣,有一天他向Fish借来翻看,但却读不懂它的意思。例如,“student. a am I”。后来才意识到,这家伙原来把句子单词的顺序翻转了,正确的句子应该是“I am a student.”。Cat对一一的翻转这些单词顺序可不在行,你能帮助他么?
思路
先翻转整体,在翻转单词。
代码
public class Solution44 {
public String ReverseSentence(String str) {
char[] chars = str.toCharArray();
int len = chars.length;
reverse(chars, 0, len - 1);
int start = 0, end = 0;
while (start < len) {
if (chars[start] == ' ') {
start++;
end++;
} else if (end == len || chars[end] == ' ') {
reverse(chars, start, --end);
start = ++end;
} else {
end++;
}
}
return new String(chars);
}
public void reverse(char[] chars, int low, int high) {
while (low < high) {
char temp = chars[low];
chars[low] = chars[high];
chars[high] = temp;
low++;
high--;
}
}
public static void main(String[] args) {
BeanUtil.print(new Solution44().ReverseSentence("student. a am I "));
}
}