02. Array Modifier

function solve(input) {

    let array = input.shift().split(' ').map(Number);

    input.forEach(element => {
        element = element.split(' ');

        let [a, b, c] = element;

        if (a === 'decrease') {
            array = array.map(function (x) {
                return x - 1
            });

        } else if (a === 'swap') {
            let valueB = array[b];
            let valueC = array[c];
            array.splice(b, 1, valueC);
            array.splice(c, 1, valueB);

        } else if (a === 'multiply') {
            let tempoA = array[b];
            let tempoB = array[c];
            let result = tempoA * tempoB;
            array.splice(b, 1, result);

        } else if (a === 'end') {
            console.log(array.join(', '));
        }
    });

}

solve(['1 2 3 4', 'swap 0 1', 'swap 1 2', 'swap 2 3', 'multiply 1 2', 'decrease', 'end']);
solve(['23 -2 321 87 42 90 -123', 'swap 1 3', 'swap 3 6', 'swap 1 0', 'multiply 1 2', 'multiply 2 1', 'decrease', 'end']);