Question

我这里有一个关于编码逻辑的问题。我必须根据百分比生成一个布尔数组。

为澄清起见，我得到一个百分比“ X”（int值），并且我想生成一个布尔数组，该布尔数组由x的1个百分数组成。而且，数组的长度是恒定的。

例如，我想基于X = 40生成布尔数组，我将：

[0,1,0,1,0,0,0,0,1,1,0,0,1,0,0,1,1,0,1,0]

我没有找到任何简单的解决方案或现有函数来生成此数组。有人可以帮我吗？

谢谢：）

Answer 1

Random shuffling of an array说明了如何对数组进行混洗。

ref_dict = dict(zip(df['REFERENCE_CODE'], df['TRANSLATION']))

Answer 2

您可以使用(Math.random() < percentage)获取 false或true，并具有所需的概率。

double percentage = 0.4; // use 0.0 <= percentage <= 1.0
boolean[] array = new boolean[100];
for (int i = 0; i < array.length; i++) {
    array[i] = (Math.random() < percentage);
}

Answer 3

这是为您提供的一种方法：

<!DOCTYPE html>
<html>

<head>
  <base target="_top">
  <script src="https://code.jquery.com/jquery-3.3.1.js" integrity="sha256-2Kok7MbOyxpgUVvAk/HJ2jigOSYS2auK4Pfzbm7uH60=" crossorigin="anonymous">
  </script>
  <script src="https://code.jquery.com/jquery-1.12.4.js"></script>
  <script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/locale/af.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/fullcalendar/3.10.0/fullcalendar.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/fullcalendar/3.10.0/fullcalendar.min.css"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/fullcalendar/3.10.0/fullcalendar.print.css"></script>
  <script>
    $(function() {
      console.log($('#calendar'))
      $('#calendar').fullCalendar({
        defaultView: 'defaultView: "month"'
      });
    })
  </script>
</head>

<body>
  <!--  The calendar  -->
  <div id="calendar">

  </div>
</body>

</html>

输出：

import java.util.Arrays;
import java.util.Collections;
import java.util.List;    

public class RandomizeArray {    

    public static void main(String args[]) {
        Boolean[] myArray = new Boolean[40];
        int xPercentage = 40;
        int ratio = myArray.length * xPercentage / 100;

        Arrays.fill(myArray, Boolean.FALSE);

        for(int i = 0; i<ratio; i++) {
            myArray[i] = true;
        }

        List<Boolean> l = Arrays.asList(myArray);
        Collections.shuffle(l);

        System.out.println(l);

    }    

}

Answer 4

考虑一个实用程序功能，我在许多用例中都很方便，例如：

// Bases on {@link java.util.Random#ints(int, int)}, but "with uniqueness and limit".
static IntStream uniqueInts(int min, int max, int count, java.util.Random rnd) {
    // check parameters ... (max > min), (max - min > count), (rnd != null...)
    // call Random.ints(min, max) with distinct and limit
    return rnd.ints(min, max).distinct().limit(count);
}

，然后再用BitSet应用于您的情况...，因为我讨厌这样的事实：“每个boolean浪费7位”：

static BitSet randomBits(int total, int goodPercent, Random rand) {
    final BitSet bitSet = new BitSet(total);
    uniqueInts(0, total,  total * goodPercent / 100, rand)
        .forEach(i -> {
            bitSet.set(i);
        });
    // bitsSet.cardinality() == total * goodPercent / 100 (!)
    return bitSet;
}

..最后（打印和主要方法）：

static void printBits(int length, BitSet bs, PrintStream out) {
    int i = 0;
    out.append('[');
    for (; i < bs.length(); i++) {
        out.append(bs.get(i) ? '1' : '0');
    }
    // fill with zeros (according to BitSet.length() definition...
    // and provide parameter, since BitSet lacks this information).
    for (; i < length; i++) {
        out.append('0');
    }
    out.append(']');
    out.println();
}

public static void main(String[] args) {
    int total = 20;
    int goodPercent = 40;
    Random rand = new Random();
    // repeat it total times, to make a nice square
    for (int i = 0; i < total; i++) {
        BitSet test = randomBits(total, goodPercent, rand);
        printBits(total, test, System.out);
    }
}

输出：

[01100011011001010000]
[01100000000101011110]
[00000101101110001001]
[01001001000110100110]
[01001110100001110000]
[00100110011100000011]
[01011100001011001000]
[00000011101101100010]
[11101000110000010010]
[01010100100011011000]
[10000101100010001101]
[00100001110010110001]
[01100000010111100001]
[10000001110101000110]
[00001010011010100011]
[01101000001110100001]
[01000100110000101101]
[00110000001010011110]
[10011011100000000011]
[01011000010111000100]

从百分比生成Java数组

4 个答案: