96. 不同的二叉搜索树

var numTrees = function(n) {
  const G = Array(n + 1).fill(0)
  G[0] = 1
  G[1] = 1

  for (let i = 2; i <= n; i++) {
    for (let j = 1; j <= i; j++) {
      G[i] += G[j - 1] * G[i - j]
    }
  }

  return G[n]
}

console.log(numTrees(3))