使用Javascript - 在范围生成随机数，不包括某些电话号码 [英] Javascript - Generating Random numbers in a Range, excluding certain numbers

问题描述

基本上我创建一个网格并在其上绘制点，并且没有两个点可以是对相同的位置[（3,4）比不同（4,3）]。的y坐标都必须在2和7（SO 2，3，4，5，6，7）和x坐标必须在1和7我有一个getRandom功能（其在下面可以看到），它生成一个一个最小值和最大值之间的范围内的随机数。这里是我到目前为止所。

Basically I am creating a grid and plotting points on it, and no two points can be on the exact same place [(3,4) is different than (4,3)]. The y coordinates have to be within 2 and 7 (so 2, 3, 4, 5, 6, 7) and x coordinates have to be within 1 and 7. I have a getRandom function (which can be seen below) which generates a random number between a min and max range. Here is what I have so far.

var xposition = [];
var yposition = [];
var yShouldBeDifferentThan = []

function placeRandom() {
    for (s=0; s<xposition.length ; s++ ) {
        if (xposition[s] == x) { // loops through all numbers in xposition and sees if the generated x is similar to an existing x
             yShouldBeDifferentThan.push(yposition[s]); //puts the corresponding y coordinate into an array.
             for (r=0; r<yShouldBeDifferentThan.length; r++) {
                 while (y == yShouldBeDifferentThan[r]) {
                     y = getRandom(2,7);
                 }
             }
        }
    }
    xposition.push(x);
    yposition.push(y);
}

这里的问题是，如果

The problem with this is, if

xposition = [1, 5, 5, 7, 5, 5]
yposition = [1, 3, 7, 2, 3, 6]
yShouldBeDifferentThan = [3, 7, 3, 6]

首先，它会生成一个随机数不同thah 3，说6.然后（我觉得）它会看到： 6 == 7 ？它没有。 6 == 3 ？它没有。的 6 == 6 ？它，所以产生比6。这是哪里出了问题来了，它可能会产生数量3.我的不同的随机数 getRandom 函数如下：

First, it will generate a random number different thah 3, say 6. Then (I think) it will see: 6 == 7? It doesn't. 6 == 3? It doesn't. 6 == 6? It does, so generate a random number different than 6. This is where the problem comes, it might generate the number 3. My getRandom function is the following:

function getRandom(min, max) {
    return min + Math.floor(Math.random() * (max - min + 1));
}

我想制作 getRandom 函数，这样我可以排除号码以及如果我想，但我不知道如何做到这一点。如果我能得到它排除数字，比上一次，而 placeRandom 函数的循环，也许我可以做这样的事情：

I was thinking making the getRandom function such that I can exclude numbers as well if I want, but I don't know how to do this. If I can get it to exclude numbers, than in the last while loop of the placeRandom function, maybe I can do something like:

y = getRandom(2,7) // excluding all numbers which already exist in the ShouldBeDifferentThan array

另外请注意，我不能使用的indexOf 方法，因为我使用的Internet Explorer 8。

Also, note that I cannot use the indexOf method since I am using Internet Explorer 8.

推荐答案

有两个问题你的方法：

• 您可能会选择一个x坐标为一行已经满了，这将发送code到一个死循环。

• You might pick an x coordinate for a row that is already full, which would send the code into an eternal loop.

采摘的x坐标，然后一个y坐标位置都会有不同的机会，这取决于有多少职位同一行前被挑选被拾起的手段。

Picking an x coordinate and then a y coordinate means that positions will have a different chance to be picked depending on how many positions were picked in the same row before.

而不是只挑选一个X和Y坐标，并检查是否具体坐标之前采摘。如果是，重新来过。

Instead just pick an x and y coordinate, and check if that specific coordinate was picked before. If it was, start over.

function placeRandom() {
  do {
    var x = getRandom(2,7), y = getRandom(2,7), found = false;
    for (s = 0; s<xposition.length; s++) {
      if (xposition[s] == x && yposition[s] == y) {
        found = true;
        break;
      }
    }
  } while(found);
  xposition.push(x);
  yposition.push(y);
}

Additionaly，当电网开始得到充分的（如80％左右），可以使包含所有其余位置的数组，并选择一个随机从。

Additionaly, when the grid starts to get full (e.g. around 80%), you can make an array containing all the remaining positions and pick one by random from that.

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