具有n个元素的数组的子集javascript [英] subsets of an arrays with n elements javascript

问题描述

我正在尝试编写一个将数组和n作为参数的函数，

I am trying to write a function that will take an array and n as parameters,

它将返回该数组的所有子集，其中包含n个元素，

it will return all subsets of that array with n elements, have tried a couple things, couldn't yet succeed.

由于有人把它放在这里，所以此功能太复杂了，无法完成工作，基本上是我试图做到的这里要做的是从4个元素的数组中挑选一个元素来创建其3个元素的子集。甚至都不需要N作为参数。它返回所有3个元素子集，但也返回相同的子集，因此我也必须将它们过滤掉，无论如何我都会继续尝试。

thanks to whoever put it here, this functions is way too complicated and doesn't do the job, basically what I tried to do here is to pick out one element from a 4 element array to create its 3 element subsets. It doesn't even take N as parameter. it returns all 3 element subsets but also identical ones, so I have to filter them out as well, in any case I will keep trying.

function findSubsets(array) { 
    var answers = []; 
    var firstArray = array; 
    for (i = 0; i < array.length; i++) { 
       array = firstArray; 
       for (var k = 0; k < array.length; k++) { 
          if (k != i) { 
              var subset = array.splice(k, 1); 
              answers.push(array); array.splice(k, 0, subset[0]);
          } 
       }
    } 
}

推荐答案

您可以尝试此解决方案

var subsetArray = (function() {
  return {
    getResult: getResult
  }

  function getResult(array, n) {

    function isBigEnough(value) {
      return value.length === n;
    }

    var ps = [
      []
    ];
    for (var i = 0; i < array.length; i++) {
      for (var j = 0, len = ps.length; j < len; j++) {
        ps.push(ps[j].concat(array[i]));
      }
    }
    return ps.filter(isBigEnough);
  }
})();

var arr = [1、2、3、4、5、6、7、8、9 ];
console.log（subsetArray.getResult（arr，2））;

var arr = [1, 2, 3, 4,5,6,7,8,9]; console.log(subsetArray.getResult(arr,2));

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