Demo code  =>

function shoot(input) {
    let targets = input.shift();
    targets = targets.split(" ").map(x => Number(x));
    let numberOfShots = 0;
    let command = input.shift();

    while (command !== 'End') {
        const index = Number(command);
        if (index < 0 || index >= targets.length || targets[index] === -1) {
            command = input.shift();
            continue;
        }

        const currentTargetNumber = targets[index];
        targets[index] = -1;
        numberOfShots++;

        for (let i = 0; i < targets.length; i++) {
            if (targets[i] === -1) {
                continue;
            }

            if (targets[i] > currentTargetNumber) {
                targets[i] -= currentTargetNumber;
            } else {
                targets[i] += currentTargetNumber;
            }
        }

        command = input.shift();
    }

    console.log(`Shot targets: ${numberOfShots} -> ${targets.join(' ')}`)
}