Delete duplicate String?

[wangdong]

Hi, I have a program that allows user to input a string from console. Then the program will delete all the duplicated words. Something like?

if user input: apple plane pen school plane
the system will return: apple plane pen school

I wrote a program to do this? All seems alright, but couldn't get a correct output? can anyone have a look?

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.StringTokenizer;

public class DeleteDup {

	/**
	 * @param args
	 */
	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		String line;
		ArrayList words = new ArrayList();
		String word;
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		line = br.readLine();
		StringTokenizer st = new StringTokenizer(line);
		words.add(st.nextToken());
		while(st.hasMoreTokens()){
			word=st.nextToken();
			for(int i=0;i<words.size();i++){
				if(words.get(i).equals(word)==false){
					words.add(word);
					break;
				}
			}
		}
		for(int i=0;i<words.size();i++){
			System.out.println(words.get(i));
		}
	}

}

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[Diancecht]

You're adding a new word just if it ins't equal to the first one. You should compare it to all the previously added ones.

Anyway, why all that stuff when Java can do it for you?

// Read the file and stuff

HashSet words = new HashSet();
StringTokenizer tk = new StringTokenizer(line);
while (tk.hasMoreTokens())
   words.add(tk.nextToken());

HassSet class will eliminate duplicate values ... and that's all folks.

Cheers,
Dian

 

[wangdong]

Hi Dian, very nice, thank you very much. I learnt how to use Hashset.

Cheers,

Dong Wang

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