剑指offer--翻转单词VS左转字符串

package Problem42;

public class ReverseSentence {
/*
* 输入一个英文句子，翻转句子中单词的顺序，但单词内字符的顺序不变
*/
public void reverseSentence(String sentence)
{
if(sentence==null)
return ;
String sentenceReverse=reverse(sentence);
String[] splitStrings=sentenceReverse.split(" ");
String resultBuffer="";
for(String s:splitStrings)
resultBuffer=resultBuffer+reverse(s)+" ";
System.out.println(resultBuffer);
}
/*
* 实现字符串左旋，abcdefg和数字2->cdefgab
*/
public void leftRotateString(String sentence,int index)
{
if(sentence==null || index>sentence.length() || index<0)
return ;
String sentenceReverse=reverse(sentence);
String[] splitStrings={sentenceReverse.substring(0,sentence.length()-index),
sentenceReverse.substring(sentence.length()-index,sentence.length())};
String resultBuffer="";
for(String s:splitStrings)
resultBuffer=resultBuffer+reverse(s);
System.out.println(resultBuffer);
}
public String reverse(String str)
{
char[] array=str.toCharArray();
for(int i=0;i<(array.length+1)/2;i++)
{
char temp=array[i];
array[i]=array[array.length-1-i];
array[array.length-1-i]=temp;
}
return String.valueOf(array);
}
}