[js] 第148天 请使用原生的js实现斐波那契数列

[haizhilin]

第148天 请使用原生的js实现斐波那契数列

[憨批必死]

let Fibonacci = num => {
    if (!Fibonacci.sequence) Fibonacci.sequence = [1, 1]
    if (Fibonacci.sequence[num] !== undefined) return Fibonacci.sequence.slice(0, num)
    for (var i = Fibonacci.sequence.length; i < num + 1; i++) {
        Fibonacci.sequence[i] = Fibonacci.sequence[i - 1] + Fibonacci.sequence[i - 2]
    }
    return Fibonacci.sequence.slice(0, num)
}

分享哈

[Joseph Compher]

function Fibonacci (n) {
  let arr = [1, 1]
  for (let i = 2; i < n + 1; i++) {
    arr[i] = arr[i - 1] + arr[i - 2]
  }
  return arr
 //return arr[n]
}

[forever-z-133]

// 使用同步缓存
function useCache(fn) {
  var cache = {};
  return function(){
    var key = Array.prototype.join.call(arguments);
    if (key in cache) return cache[key];
    else return cache[key] = fn.apply(fn, arguments);
  }
}
function fibonacci (n) {
  if ( n <= 1 ) return 1;
  return fibonacci(n - 1) + fibonacci(n - 2);
}
fibonacci = useCache(fibonacci);

[憨批必死]

// 使用同步缓存
function useCache(fn) {
  var cache = {};
  return function(){
    var key = Array.prototype.join.call(arguments);
    if (key in cache) return cache[key];
    else return cache[key] = fn.apply(fn, arguments);
  }
}
function fibonacci (n) {
  if ( n <= 1 ) return 1;
  return fibonacci(n - 1) + fibonacci(n - 2);
}
fibonacci = useCache(fibonacci);

恁这不对吧，输出8是数列

[Konata9]

const fib = (limit = 10, arr = [1, 1]) => {
  // 使用循环
  // if (limit < 3) {
  //   return arr;
  // }

  // const result = arr;
  // while (result.length < limit) {
  //   const len = result.length;
  //   result.push(result[len - 1] + result[len - 2]);
  // }
  // return result;

  // 使用递归
  if (arr.length < limit) {
    const len = arr.length;
    return fib(limit, [...arr, arr[len - 1] + arr[len - 2]]);
  } else {
    return arr;
  }
};

console.log(fib());
console.log(fib(9));

[Kevlin]

const fib=(n,sum1=1,sum2=1)=>{
if(n<1) return sum2
return fib(n-1,sum2,sum1+sum2)
}

ES6尾递归优化，严格模式有效

[abueavan]

function fibonacci(n) {
  const fibSequence = [1];

  let currentValue = 1;
  let previousValue = 0;

  if (n === 1) {
    return fibSequence;
  }

  let iterationsCounter = n - 1;

  while (iterationsCounter) {
    currentValue += previousValue;
    previousValue = currentValue - previousValue;

    fibSequence.push(currentValue);

    iterationsCounter -= 1;
  }

  return fibSequence;

[forever-z-133]

#1180 (comment)
对的吧，举个反例贴一下吧，嘤嘤嘤

[xiaoqiangz]

function Fibonacci (n) {
  let arr = [1, 1]
  for (let i = 2; i < n + 1; i++) {
    arr[i] = arr[i - 1] + arr[i - 2]
  }
  return arr
 //return arr[n]
}