A program to identify a duplicate value in a vector.:

import java.io.*;

import java.util.*;

class VectorTest

{

public static void main(String as[]) throws Exception

{

int i,j,n;

Vector v1=new Vector(10);

Vector v2=new Vector(10);

InputStreamReader isr=new InputStreamReader(System.in);

BufferedReader br=new BufferedReader(isr);

System.out.println("How many Strings:");

n=Integer.parseInt(br.readLine());

System.out.println("Enter strings:\n");

for(i=0;i

v1.add(br.readLine());

System.out.println("Vector Elements:\n"+v1);

for(i=0;i

for(j=i+1;j

if(v1.elementAt(i).equals(v1.elementAt(j)))

v2.add(v1.elementAt(j));

System.out.println("\nDuplicate Elements:\n"+v2);

}

}

/* Output: */

How many Strings:5

Enter strings:

cat

rat

mat

cat

mat

Vector Elements:

[cat, rat, mat, cat, mat]

Duplicate Elements:

[cat, mat]