這題簡(jiǎn)單的話用split函數(shù)就行了,但要注意split的用法是很奇怪的胆胰,
public String reverseWords(String s) {
String[] array = s.split(" ");
StringBuilder sb = new StringBuilder();
for (int i = array.length - 1; i >= 0; i--) {
//這一行用""作regex讥蟆,而不是" "昵时,因?yàn)閍rray里根本沒(méi)有" "了
if (!array[i].equals("") ) {
sb.append(array[i]).append(" ");
}
//這樣寫(xiě)的話就忽略了" 1"這種情況
// if (i != 0) {
// sb.append(" ");
// }
}
return sb.length() == 0 ? "" : sb.substring(0, sb.length() - 1);
}
摘抄遞歸做法:
http://blog.csdn.net/linhuanmars/article/details/20982463
public String reverseWords(String s) {
s = s.trim();
return helper(s,0).toString();
}
private StringBuilder helper(String s, int index)
{
if(index>=s.length())
return new StringBuilder();
StringBuilder cur = new StringBuilder();
int lastIndex = index;
while(index < s.length() && s.charAt(index)!=' ')
{
cur.append(s.charAt(index++));
}
while(index < s.length() && s.charAt(index)==' ')
index++;
if(lastIndex == 0)
return helper(s,index).append(cur);
return helper(s,index).append(cur).append(' ');
}
還有種方法爵赵,先反轉(zhuǎn)成"eulb si yks eht"扛或,然后在對(duì)每一個(gè)單詞反轉(zhuǎn)瓤湘,得到"blue is sky the"瓢颅。不寫(xiě)了。