Cracking the Coding Interview Chap1 Q1.3

Q1.3 Design an algorithm and write code to remove the duplicate characters in a string without using any additional buffer. 

NOTE: One or two additional variables are fine. An extra copy of the array is not.

FOLLOW UP

Write the test cases for this method.

For each character, check if it is a duplicate of already found characters

Skip duplicate characters and update the non duplicate characters

public class ccChap1_3 {public static void main(String[] args){String str = "TTestBaBa";System.out.println(str);System.out.println(removeDupStr(str));}public static String removeDupStr(String strr){char[] str =strr.toCharArray(); if (strr == null) return strr; int len = str.length; if (len < 2) return strr; int tail = 1;  for(int i=1;i<len;++i){ int j; for (j=0;j<tail;++j){ if (str[i]==str[j]) break; }if(j==tail){str[tail]=str[i];++tail;} } return new String(str, 0, tail);}}