求解逆波兰表达式(Reverse Polish Notation)

求解逆波兰表达式

const R = require("ramda");

const solveRPN =
  R.compose(
    R.head,
    R.reduce(
      (acc, item) => {
        let [x,y,...ys] = acc;
        if (item == '+') {
          return R.concat([R.add(x, y)], ys);
        } else if (item == '-') {
          return R.concat([R.subtract(x, y)], ys);
        } else if (item == '*') {
          return R.concat([R.multiply(x, y)], ys);
        } else {
          return R.concat([item], acc);
        }
      }, []
    ),
    R.split(" ")
  );
  
let log = console.log;
log(solveRPN("10 4 3 + 2 * -"));