so 简单

这已经不是easy了,是easy中的easy

let stack = [];
function push(node)
{
  stack.push(node);
}
function pop()
{
  return stack.pop();
}
function top()
{
  return stack[stack.length-1];
}
function min()
{
  let min = Infinity;
  stack.forEach(item=>min=Math.min(min,item));
  return min;
}
module.exports = {
    push : push,
    pop : pop,
    top : top,
    min : min
};