https://leetcode.com/problems/find-the-winner-of-the-circular-game

function findTheWinner(n: number, k: number): number {
    // [1, 2, ...., n]
    const friends = [...new Array(n)].map((_, ix) => ix + 1);
    let target = -1; // k=1 needs to pick the first friend, so we start before them
    for(var i=n; i > 1; i--) {
        target = (target + k) % friends.length; // increment and wrap
        friends.splice(target, 1); // remove the target
        target -= 1; // k=1 needs to pick the friend who just filled in the spot we vacated
    }
    return friends[0];
};