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Sep 12, 2024

`/* `

* For a series of 1 - n with size n + 1, find the duplicate item in the series

* [1,2,3,4,5,3] -> 3

* [1,2,3,4,1] -> 1

*/

function getDuplicate(arr){

const sum = ((arr.length - 1) * (arr.length))/2

let diff = 0;

for(let i = 0 ; i < arr.length ; i++) {

diff = diff - arr[i];

}

let duplicate = sum + diff;

return Math.abs(duplicate); // gives back the duplicate element

}

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