Find the Duplicate Number Problem Statement

Given an integer array 'ARR' of size 'N' containing numbers from 0 to (N - 2). Each number appears at least once, and there is one number that appears twice. Your task is to find and return this duplicate number.

Example:

Input:

t = 1
N = 5
ARR = [0, 3, 1, 2, 3]

Output:

3

Explanation:

The number '3' is the duplicate because it appears twice in the array.

Constraints:

1

Question

Find the Duplicate Number Problem Statement

Given an integer array 'ARR' of size 'N' containing numbers from 0 to (N - 2). Each number appears at least once, and there is one number that appears twice. Your task is to find and return this duplicate number.

Example:

Input:

t = 1
N = 5
ARR = [0, 3, 1, 2, 3]

Output:

Explanation:

The number '3' is the duplicate because it appears twice in the array.

Constraints:

1 <= t <= 10^2
0 <= N <= 10^3
Time Limit: 1 sec

Note:

The duplicate number is always present in the given array.

Accepted Answer

Given an array of size N containing numbers from 0 to (N-2), find and return the duplicate number.

Iterate through the array and keep track of the frequency of each number using a hashmap.
Return the number with a frequency of 2.

Accepted Answer

List not allowed duplicate values

Accepted Answer

First find xor of all the element between 1 to n in o(1) using n%4 trick and then xor the result with all the elements of array linearly. PS: if you don't know the n%4 trick... here it is https://www.geeksforgeeks.org/calculate-xor-1-n/amp/

Accepted Answer

Duplicate values are not allowed

Accepted Answer

List not allowed duplicate values

Accepted Answer

List not allowed duplicate values

Accepted Answer

http,

if

int array size 'N';

else,number 0 to (N-2);

goto (if) (else)

do

number presentt once,

print,N=5,;

while,array ranging 0 to3,

and

if single integers present twice,;

goto,if else;

(break) the number integers,

(return) to the number integers;

end,,,;

Accepted Answer

Set unique = new HashSet();
List duplicateList = Arrays.of(inputArray);

duplicateList.stream().filter(s-> !unique.add(s)).forEach(System.out.println);

Accepted Answer

Sure, I can help you with that. Here is the algorithm to find the duplicate number in an array:

Iterate through the array and create a set of all the elements in the array.
Iterate through the set and check if any element appears more than once.
If an element appears more than once, return that element as the duplicate number.

Here is an example of how to use the algorithm: