保持單詞之間的空格位數不變，而不是簡單的分割字串後再分別反轉

public class MyReverseWords {

    public static void main(String[] args) {
        String str = "how are     you   ?  ";
        char[] chars = str.toCharArray();
        reverseWords(chars);
        System.out.println(new String(chars));
    }

    /**
     * 將字元陣列的單詞分別反轉,並保持空格間距不變
     * 如how are     you   ?==>ohw rae     oyu   ?
     * @param
 
 chars
     */
    public static void reverseWords(char[] chars) {

        int begin = -1;
        int end = 0;

        for (int i = 0; i < chars.length; i++) {
            char c = chars[i];
            if (c != ' ') {//判斷是否為單詞，如果是，則標記

                if(begin == -1){
                    begin = i;
                    end = i;
                }else
 
{
                    end = i;
                    reverseChars(chars, begin, end);
                }

            }else{
                //一個單詞結束，進行反轉操作
                if(begin != -1){
                    reverseChars(chars, begin, end);
                }
                begin=-1;
                //end = 0;
 

            }
        }
    }

    /**
     * 反轉字元陣列的指定範圍
     * @param chars
     * @param begin
     * @param end
     */
    public static void reverseChars(char[] chars , int begin , int end){
        while(begin < end){
            char swap = chars[begin];
            chars[begin] = chars[end];
            chars[end] = swap;
            begin++;
            end--;
        }
    }

}