Math

main.js

const get_all_opreations = (operators = ["+", "-", "*", "/"], length = 3) =>
{
    const generate_combinations = (current, depth) =>
    {
        if (depth === 0)
        {
            return [current];
        }
        return operators.flatMap(op => generate_combinations([...current, op], depth - 1));
    };
    return generate_combinations([], length);
}

const evaluate_expression = (numbers = [1,1,1,1], operators = ["+", "-", "*", "/"]) =>
{
    let result = numbers[0];
    for (let i = 0; i < operators.length; i++)
    {
        const operator = operators[i];
        const number = numbers[i + 1];
        if (operator === "+") result += number;
        else if (operator === "-") result -= number;
        else if (operator === "*") result *= number;
        else if (operator === "/") result /= number;
    }
    return result;
}

const main = (input = [], target_result = 0) =>
{
    const opreators = ["+", "-", "*", "/"];
    const all_opreators = get_all_opreations(opreators);
    for (let i = 0; i < all_opreators.length; i++)
    {
        const current_operators = all_opreators[i];
        const result = evaluate_expression(input, current_operators);
        if (result === target_result)
        {
            console.log(i, current_operators);
            return current_operators;
        }
    }
    console.log(-1, null);
    return null;
};

const input = [6,6,6,6];
const result = 0;
main(input, result);