aaaaaa.js

function solution(dartResult) {
  const answer = dartResult.match(/(\d+|\D)/g).reduce((p, c) => {
    let n = 0;
    switch(c) {
      case '*' :
        const n1 = p.pop();
        const n2 = p.pop();

        if(n2) p.push(n2 * 2);
        p.push(n1 * 2);

        break;
      case '#' :
        n = p.pop();
        p.push(n * -1);
        break;
      case 'S' :
        break;
      case 'D' :
        n = p.pop();
        p.push(n * n);
        break;
      case 'T' :
        n = p.pop();
        p.push(n * n * n);
        break;
      default:
        p.push(+c);
    }

    return p;
  }, []);

  return answer.reduce((p, c) => p + c, 0);
}