[置顶] 剑指offer：第42题反转单词顺序VS左旋转字符串

常规思路：就是按照普通字符串拆分-添加完成的……
public class Solution {
public String ReverseSentence(String str) {
if(str == null){ return null;}
if(str.trim().equals("")){
return str;
}
String string = str;
String[] strings = string.split(" ");
StringBuilder sBuilder = new StringBuilder();
for (int i = strings.length-1 ; i>=0;i--) {
if(i == 0){
sBuilder.append(strings[i]);
}else {
sBuilder.append(strings[i]);
sBuilder.append(" ");
}
}

String string2 = sBuilder.toString();
return string2;
}
}