基于值绑定填充数组

Question

我需要创建一个基于一个人的“年龄”的数据数组。这种带状结构不是线性的，而是像这样分组的

1,2,3,4,5,6,7,8,9,10,11-15,16-20,21-30,31-50,51+

因此，对于任何一组数据，我都需要遍历这些数据，并将其放入适当的年龄“桶”中。

在循环的最后，我想看看每个带中有多少人。

现在，我已经使用了非常粗糙的技术来做到这一点(也就是如果..然后..。否则..。) ;)，但是我想知道我是否可以学习新的技术，以及是否有任何库或函数可以接受范围并相应地填充存储桶

Answer 1

这就是我要做的：

let buckets = '1,2,3,4,5,6,7,8,9,10,11-15,16-20,21-30,31-50,51+'.split(','),
    bucketByAge = {}; // our bucket-age connector where we search later on

// prepare the index
buckets.forEach(function(bucket, index) {
  // get the range (+ will be replaced with 1000; for the age it is infinity)
  // and transform them to numbers
  let range = bucket.replace('+', '-1000').split('-').map(Number);

  // if it was not a range, simulate one
  range[1] = range[1] || range[0];

  // go through the range and fill our connector
  while (range[0] <= range[1]--) {
    bucketByAge[range[1]] = index;
  }
});

// search
function getBucket(age) {
  return { age: age, bucketRange: buckets[bucketByAge[age]], bucketIndex: bucketByAge[age] };
}

console.log(getBucket(1));
console.log(getBucket(12));
console.log(getBucket(61));

这里的好处是:您只需构建一次索引，然后获取结果即可。非常好的表现。

Answer 2

一个非常粗糙的o(n^2)实现

​

const buckets = [
  {
    lowerLim: 1,
    upperLim: 1,
    persons: 0
  },
  {
    lowerLim: 2,
    upperLim: 2,
    persons: 0
  },
  {
    lowerLim: 3,
    upperLim: 5,
    persons: 0
  },
  {
    lowerLim: 6,
    upperLim: 10,
    persons: 0
  },
  {
    lowerLim: 11,
    persons: 0
  }
];


const persons = [{name: 'john', age: 1},{name: 'john', age: 2}, {name: 'john', age: 6}, {name: 'john', age: 20}, {name: 'john', age: 40}, {name: 'john', age: 7}, {name: 'john', age: 1}];

persons.forEach(person => {
  buckets.forEach(bucket => {
    const age = person.age;
    const bucketLowerLimit = bucket.lowerLim;
    const bucketUpperLimit = bucket.upperLim || Number.MAX_SAFE_INTEGER;

    if(age >= bucketLowerLimit && age <= bucketUpperLimit) {
      bucket.persons++;
    }
  })
});


buckets.forEach(bucket => {
  console.log(bucket.persons);
});

​

Answer 3

您可以对inbetween中的所有值和单独的最后一个值使用引用。

​

var slots = '1,2,3,4,5,6,7,8,9,10,11-15,16-20,21-30,31-50,51+'.split(','),
    last = slots.pop(),
    reference = Object.create(null),
    histogram = Object.create(null),
    i, value;

slots.forEach(function (a) {
    var temp = a.split('-'),
        left = temp[0],
        right = temp[1] || temp[0];

    histogram[a] = 0;
    reference[right] = a;
    while (left < right) {
        reference[left] = a;
        left++;
    }
});

histogram[last] = 0;

for (i = 0; i < 1000000; i++) {
    value = Math.floor(Math.random() * 100);
    histogram[reference[value] || last]++;
}

console.log(histogram);
console.log(reference);

.as-console-wrapper { max-height: 100% !important; top: 0; }

​