function fibonacci(n) { return fib(n)[n] } var fib=(function(n){ var meo=[0,1] return function(n){ for(var i=meo.length;i<=n;i++){ meo[i]=meo[i-1]+meo[i-2] } return meo.slice(0,n+1) } })()
以上空间复杂度：o(n)，时间复杂度：o(n)，最快 o(1)
2.运用大数加法：
var _fib = (function (n) { var memory = [‘0‘, ‘1‘]; function add(a, b) { var res = ‘‘, c = 0; a = a.split(‘‘); b = b.split(‘‘); while (a.length || b.length || c) { c += ~~a.pop() + ~~b.pop(); res = c % 10 + res; c = c > 9; } return res.replace(/^0+/, ‘‘); } return function (n) { for (var i = memory.length; i <= n; i++) { memory[i] = add(memory[i - 1], memory[i - 2]); } //console.log(memory.length + ‘ numbers saved.‘); return memory.slice(0, n + 1); }; })(); var fibonacci = function (n) { return _fib(n)[n]; }