CareerCup

Keep storing in the HashMap..?

HashMap or helper hashset or othe (e.g tree) index on array,if data have to be strored in array for any reason

Generally with some form of hash structure.

If you can't have another data structure, I guess it depends on the input data and the definition of 'scanned'. If faster than O(N) does not count as 'scanned' then you could insert the elements in sorted order and then discover whether an element is duplicate in O(log(N)).
If the input data is of a limited range (say integers from 0-100) then you could encode each value as a bit in a sequence of bytes and switch it to 1 when the element is entered, and then check if the bit is 1 whenever a new element is entered, rejecting the entry if the bit is already 1.

What ever it may be Hash Map or Hash set, before inserting value it scans the complete array, So thts not the solution, May be we can use some trees, which was already sorted.

package com.kavitha.selfhelp;

import java.util.HashSet;
import java.util.Set;

public class StoreSet {

public static void main (String[] args){
Set <Integer> sampleset = new HashSet<Integer>();
System.out.println("No repetition see below: ");
for (String s : args){
Integer input = Integer.parseInt(s);
sampleset.add(input);
}

for(Integer setint : sampleset){
System.out.println( setint );
}
}
}

what are the input values? is it just characters or can be anything?

int countingTable[128] = {0}; (Assuming ascii character set)
while (1) {
cin >> character;
if (countingTable[character] == 1) {
cout << "duplicate";
} else {
countingTable[character] = 1;
}
}