This is a cup of tea string flip problem ......

The This is a cup of tea into
tea of ​​cup a is This
finished writing the code did not find that last turn or sihT This

public class TheSwap {
  
      /**
       * @param args the command line arguments
       */
      public static void main(String[] args) {
          // TODO code application logic here
          String str="This is a cup of tea";
          char[] chr=str.toCharArray();
          for(char ele:chr){
              System.out.print(ele);
          }
          int l=chr.length;
          for(int i=0;i<l/2;i++){
              char temp=chr[i];
              chr[i]=chr[l-i-1];
              chr[l-i-1]=temp;
          }
          System.out.println();
          for(char ele:chr){
              System.out.print(ele);
          }
          System.out.println();
          swapIn(chr);
          System.out.println("FINAL IS:");
          for(char ele:chr){
              System.out.print(ele);
          }
      }
      
      private static void swapIn(char[] c){
          int count=0;
          for(int i=0;i<c.length;i++){ 
              if(c[i]!=' '){
                  count++;
                  continue;
          }
              if(c[i]==' ' || (i==c.length-1)){
                  if(count==1){
                      count=0;
                      continue;
                  }
                  else{
                      int tempCount=0;
                      for(int j=i-count;j<i-Math.floor(count/2);j++){
                          char ctemp=c[j];
                          c[j]=c[i-1-tempCount];
                          c[i-1-tempCount]=ctemp;
                          tempCount++;
                      }
                      count=0;
                  }
              }
          }
          
      }
  }

------ Solution ------------------------------------- -------
LZ head to see the code to a simple point ~

  public class TheSwap {
  	public static void main(String[] args) {
  		String str = "This is a cup of tea";
  		char[] arr = str.toCharArray();
  		System.out.println("before:" + str);
  		swapIn(arr);
  		System.out.println("after:" + String.valueOf(arr));
  	}
  
  	private static void swapIn(char[] arr) {
  		if(arr.length == 0) return;//空串
  		//反转整个字符串
  		rotate(arr, 0, arr.length - 1);
  		//以空格区分，逐个反转子字符串
  		int count = 0;//非空格字符数量
  		for(int i = 0;i < arr.length;++i) {
  			if(arr[i] != ' ') ++count;
  			else {
  				rotate(arr, i - count, i - 1);
  				count = 0;
  			}
  		}
  		//反转最后一个字符串
  		rotate(arr, arr.length - count, arr.length - 1);
  	}
  	
  	//反转字符串
  	private static void rotate(char[] arr,int start,int end) {
  		for(int i = start;i <= (start + end) / 2;++i) {
  			char temp = arr[i];
  			arr[i]= arr[end - (i - start)];
  			arr[end - (i - start)] = temp;
  		}
  	}
  }
  

------ For reference only ---------------------------------------

String str="This is a cup of tea ";
          String arr [] = str.split(" ");
          for (int i=arr.length-1; i>=0; i--) {
              System.out.print(arr[i] + " ");
          }

- ----- For reference only ---------------------------------------

not split (), I forgot to say, is to write a reverse algorithm , can not use an existing function .
------ For reference only -------------------------------------- -
string split it. You converted to char too much trouble . Recommendations upstairs .
------ For reference only -------------------------------------- -
amount is not stated clearly
The purpose of this program is to write an O (n) algorithm
Also, do not use any existing functions , of course I know that split, if the interviewer can not let you use it ?
------ For reference only -------------------------------------- -
converted to char is because the problem is actually located was originally a char [] array where the program is to facilitate one by one with a tochar avoid assignment
------ For reference only - -------------------------------------
can refer to:

  public static String reverse(String source){
  	String[] array = source.split(" ");  //分割字符串得到单词数组
  	int length = array.length;  //数组元素的个数
  	int count = length / 2; //数组元素首尾交换需要的趟数
  	String temp;
  	for(int i = 0; i < count; i++){ //首尾交换数组元素的位置, 0和length-1交换, 1和length-2交换...
  		temp = array[i];
  		array[i] = array[length - i - 1];
  		array[length - i - 1] = temp;
  	}
  	//将数组转为String
  	StringBuilder target = new StringBuilder();
  	for(int i = 0; i < length; i++){
  		target.append(array[i]).append(" ");
  	}
  	return target.deleteCharAt(source.length()).toString();
  }
  

Or:

  public static String reverse(String source){
  	StringBuilder sb = new StringBuilder();
  	String[] sources = source.split(" "); //分割字符串得到单词数组
  	for(String s : sources){
  		//在第0号位置插入单词，原先在第0号的单词就会不断的往后移，最先进来的被移动最后面
  		sb.insert(0, s + " "); 
  	}
  	return sb.deleteCharAt(sb.length() - 1).toString();
  }
  

------ For reference only ----------------------------------- ----

ah can only be this line of thinking only of my own to make a change I do not know where the problem is actually with you out of the same ideas < br>