kaixinbingju的专栏

package question1_2; public class Question { public static String reverseString(String str){ if(str.equals(null)){ return null ; } StringBuffer sBuffer=new StringBuffer(str); String strResu

package question1_1; /*  * Implement an algorithm to determine if a string has all unique characters  */ public class Question { //位操作 public static boolean isUniqueChars1(String str){ if(s