Run results for: Find Duplicate: sort, set, floyd

Test name	Executions per second
sort	966211.8 Ops/sec
Set	980879.4 Ops/sec
floyd	41363720.0 Ops/sec

sort

const dupearray1 = [1,8,4,5,9,3,7,4,6,2];

let sortResult = 0;
function sortMethod(array){
    let prev = 0;
    array
    .sort()
    .forEach(element =>{
        if(element === prev) {
            sortResult = element;
        }
        if (element !== prev){
            prev = element;
        } 
    });
}
sortMethod(dupearray1);

Set

const dupearray2 = [1,8,4,5,9,3,7,4,6,2];

let setResult = 0;
function setMethod(array){
    let seen = new Set();
    return array.forEach(element => {
        if(!seen.has(element)){
            seen.add(element);
        } else{
            setResult = element;
            return setResult;
        }
    });
}
setMethod(dupearray2);

floyd

const dupearray3 = [1,8,4,5,9,3,7,4,6,2];

let floydResult = 0;

function floyd(array){

    let tortoise = array[0];
    let hare = array[array[0]];

    while(hare !== tortoise){
        tortoise = array[tortoise];
        hare = array[array[hare]];
    }
    hare = 0;
    while (tortoise !== hare){
        tortoise = array[tortoise];
        hare = array[hare];
    }
    floydResult = tortoise;
    return tortoise;
}

floyd(dupearray3);

Run results for: Find Duplicate: sort, set, floyd

Find the fastest method of finding duplicates

sort

Set

floyd