java实现字符串反转【全】

时间:2025-04-04 12:23:27

package ;
 
import ;
 
/**
 * 8 种字符串反转的方法, 其实可以是9种方法,第9种是使用StringBuffer和StringBuilder中实现的方法
 * @author Josh Wang(Sheng)
 *
 * @email  swang6@
 *
 */
public class StringReverse {
 
    /**
     * 二分递归地将后面的字符和前面的字符连接起来。
     *
     * @param s
     * @return
     */
    public static String reverse1(String s) {
        int length = ();
        if (length <= 1)
            return s;
        String left = (0, length / 2);
        String right = (length / 2, length);
        return reverse1(right) + reverse1(left);
    }
     
    /**
     * 取得当前字符并和之前的字符append起来
     * @param s
     * @return
     */
    public static String reverse2(String s) {
        int length = ();
        String reverse = "";
        for (int i=0; i<length; i++)
            reverse = (i) + reverse;
        return reverse;
    }
     
    /**
     * 将字符从后往前的append起来
     * @param s
     * @return
     */
    public static String reverse3(String s) {
        char[] array = ();
        String reverse = "";
        for (int i =  - 1; i >= 0; i--) {
            reverse += array[i];
        }
        return reverse;
    }
     
    /**
     * 和StringBuffer()一样,都用了Java自实现的方法,使用位移来实现
     * @param s
     * @return
     */
    public static String reverse4(String s) {
        return new StringBuilder(s).reverse().toString();
    }
     
    /**
     * 和StringBuilder()一样,都用了Java自实现的方法,使用位移来实现
     * @param s
     * @return
     */
    public static String reverse5(String s) {
        return new StringBuffer(s).reverse().toString();
    }
     
    /**
     * 二分交换,将后面的字符和前面对应的那个字符交换
     * @param s
     * @return
     */
    public static String reverse6(String s) {
        char[] array = ();
        int end = () - 1;
        int halfLength = end / 2;
        for (int i = 0; i <= halfLength; i++) {
            char temp = array[i];
            array[i] = array[end-i];
            array[end-i] = temp;
        }
         
        return new String(array);
    }
     
    /**
     * 原理是使用异或交换字符串
     * a=a^b;
     * b=b^a;
         * a=b^a;
     *
     * @param s
     * @return
     */
    public static String reverse7(String s) {
        char[] array = ();
           
          int begin = 0;
          int end = () - 1;
           
          while (begin < end) {
               array[begin] = (char) (array[begin] ^ array[end]);
               array[end] = (char) (array[end] ^ array[begin]);
               array[begin] = (char) (array[end] ^ array[begin]);
               begin++;
               end--;
          }
           
          return new String(array);
    }
     
    /**
     * 基于栈先进后出的原理
     *
     * @param s
     * @return
     */
    public static String reverse8(String s) {
        char[] array = ();
        Stack<Character> stack = new Stack<Character>();
        for (int i = 0; i < ; i++)
            (array[i]);
 
        String reverse = "";
        for (int i = 0; i < ; i++)
            reverse += ();
           
        return reverse;
    }
     
    public static void main(String[] args) {
        (reverse1("Wang Sheng"));
        (reverse2("Wang Sheng"));
        (reverse3("Wang Sheng"));
        (reverse4("Wang Sheng"));
        (reverse5("Wang Sheng"));
        (reverse6("Wang Sheng"));
        (reverse7("Wang Sheng"));
        (reverse8("Wang Sheng"));