Question

我有一个整数X和X的所有因子的列表。我想输出X和因子之间的比率，并且每次将X设置为该比率。我希望这个算法继续，直到比率大于或等于1.

例如：X = 36。

所有因素（但1和36）：2,3,4,6,9,12,18，

算法：36/2 = 18 - ＆gt; 18/3 = 6 - ＆gt; 6/4 = 1.5 - ＆gt; 1.5 / 6＆lt; 1 - ＆gt;停止

输出：[18,6,1.5]。问题：

如何获得此输出？

我写的：

var arr = [];

  for (var i = 2; i < X; i++) {
    if (X % i == 0) {
      arr.push(i);
    }
  }

  var temp = [];

  var index = 0;
  while (X / arr[index] >= 1) {
    index += 1;
    X = X / arr[index];
    temp.push(X / arr[index]);
  }

Answer 1

您可以在进入while循环之前计算第一个值并检查asssigned x。如果值超过条件，则可以将该值推送到结果数组并增加索引并计算新值。

＆＃13;

function fn(x) {
    var array = [],               // declare all variable on top
        i,
        result = [];

    for (var i = 2; i < x; i++) {
        if (x % i == 0) {
            array.push(i);
        }
    }
    i = 0;                        // prepare index for looping
    x /= array[i];                // take a first possible value
    while (x >= 1) {              // check value
        result.push(x);           // push value
        i++;                      // increment index
        x /= array[i];            // take the next value for checking
    }
    return result;
}

console.log(fn(36))

＆＃13;

Array#every

稍短

＆＃13;

function fn(x) {
    var array = [],               // declare all variable on top
        i,
        result = [];

    for (var i = 2; i < x; i++) {
        if (x % i == 0) {
            array.push(i);
        }
    }
    array.every(v => (x /= v) >= 1 && result.push(x));
    return result;
}

console.log(fn(36))

＆＃13;

Answer 2

＆＃13;

var arr = [];
  var X = 36
  for (var i = 2; i < X; i++) {
    if (X % i == 0) {
      arr.push(i);
    }
  }
  
  var temp = arr.reduce((acc, item, index) => {
      if(!(X/item < 1)){
          acc.push(X/item)
          X = X/item;
      }
      return acc;
  }, [])
  
  console.log(temp)

＆＃13;

Answer 3

你的问题有点混乱。这是你想要的吗？

基本上，我在每次迭代后更新因子（如果＆gt; = 1）并将输出存储到数组中。

＆＃13;

// Generate a range of integers (starting at 2, and we should not including the input)
// get only values divisible by the input (filter)
const generateRange = (input) => {
  return Array.from({length: (input - 2)}, (v, k) => k + 2).filter(i => {
    return input % i === 0;
  })
}

const divideFactors = (input) => {
  const list = generateRange(input) // filtered range
  let output = [] 
  let factor = input 
  
  for (const item of list) {
    let ratio = factor / item

    if (ratio < 1) { //if ratio < 1, break the loop
      break;
    }     
    
    output.push(ratio) // update output array with new ratio
    factor = ratio; // update factor variable with current ratio
  }

  return output
}

console.log(divideFactors(36))

＆＃13;

更多信息：

Array.from： https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from

适用于： https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of

按因素划分

3 个答案: