使用JavaScript计数排序可视化

GUI(图形用户界面)比程序更能帮助您理解。在本文中，我们将使用JavaScript可视化计数排序。我们将看到如何存储元素的频率以及如何获得最终的排序数组。我们还将可视化计数排序的时间复杂度。

参考：

• 计数排序
• JavaScript中的异步函数

方法：

• 首先，我们将使用Math.random()生成一个随机数组 函数。
• 使用不同的颜色来表示要遍历哪个元素。
• 另一个数组用于存储给定元素的频率。
• 由于该算法执行速度非常快，因此 setTimeout() 函数已被用来减慢该过程。
• 可以通过按“ Ctrl + R”键来生成新数组。
• 使用CountingSort()函数执行排序。

例子：

排序之前

排序后

下面是可视化计数排序算法的程序。所有节代码都一一涵盖。

index.html

  
    
  
  
  
    
    Counting Sort
  
  
    
    
    
  
    
  
    
  

style.css

* {
  margin: 0px;
  padding: 0px;
  box-sizing: border-box;
}
  
.header {
  font-size: 20px;
  text-align: center;
}
  
#array {
  background-color: white;
  height: 265px;
  width: 598px;
  margin: auto;
  position: relative;
  margin-top: 64px;
}
  
.block {
  width: 28px;
  background-color: #6b5b95;
  position: absolute;
  bottom: 0px;
  transition: 0.2s all ease;
}
  
.block2 {
  width: 28px;
  background-color: darkgray;
  position: absolute;
  transition: 0.2s all ease;
}
.block_id {
  position: absolute;
  color: black;
  margin-top: -20px;
  width: 100%;
  text-align: center;
}
.block_id2 {
  position: absolute;
  color: black;
  margin-top: 22px;
  width: 100%;
  text-align: center;
}
  
.block_id3 {
  position: absolute;
  color: black;
  margin-top: 1px;
  width: 100%;
  text-align: center;
}
  
#count {
  height: 265px;
  width: 598px;
  margin: auto;
}

script.js

var container = document.getElementById("array");
  
// Function to generate the array of blocks
function generatearray() {
  for (var i = 0; i < 20; i++) {
    // Return a value from 1 to 100 (both inclusive)
    var value = Math.ceil(Math.random() * 20);
  
    // Creating element div
    var array_ele = document.createElement("div");
  
    // Adding class 'block' to div
    array_ele.classList.add("block");
  
    // Adding style to div
    array_ele.style.height = `${value * 13}px`;
    array_ele.style.transform = `translate(${i * 30}px)`;
  
    // Creating label element for displaying
    // size of particular block
    var array_ele_label = document.createElement("label");
    array_ele_label.classList.add("block_id");
    array_ele_label.innerText = value;
  
    // Appending created elements to index.html
    array_ele.appendChild(array_ele_label);
    container.appendChild(array_ele);
  }
}
  
// Function to generate the frequency array
var count_container = document.getElementById("count");
function generate_freq() {
  for (var i = 0; i < 20; i++) {
    // Creating element div
    var array_ele2 = document.createElement("div");
  
    // Adding class 'block2' to div
    array_ele2.classList.add("block2");
  
    // Adding style to div
    array_ele2.style.height = `${20}px`;
    array_ele2.style.transform = `translate(${i * 30}px)`;
  
    // index of freq array
    var array_ele_idx = document.createElement("label");
    array_ele_idx.classList.add("block_id2");
    array_ele_idx.innerText = i + 1;
  
    //giving initial freq to all blocks as 0
    var array_ele_label2 = document.createElement("label");
    array_ele_label2.classList.add("block_id3");
    array_ele_label2.innerText = 0;
  
    // Appending created elements to index.html
    array_ele2.appendChild(array_ele_label2);
    array_ele2.appendChild(array_ele_idx);
    count_container.appendChild(array_ele2);
  }
}
  
// Asynchronous CountingSort function
async function CountingSort(delay = 250) {
  var blocks = document.querySelectorAll(".block");
  
  // To store frequency of every block
  for (var i = 0; i < blocks.length; i += 1) {
    //To highlight the current traversed block
    blocks[i].style.backgroundColor = "#FF4949";
  
    //Extracting the value of current block
    var value = Number(blocks[i].childNodes[0].innerHTML);
  
    var freq_array = document.getElementsByClassName("block_id3");
  
    freq_array[value - 1].innerText++;
  
    // To wait for .1 sec
    await new Promise((resolve) =>
      setTimeout(() => {
        resolve();
      }, delay)
    );
  
    //Changing to previous color
    blocks[i].style.backgroundColor = "#6b5b95";
  }
  
  //Sorting by using frequency array
  var idx = 0;
  for (var i = 0; i < blocks.length; i += 1) {
    var freq = document.getElementsByClassName("block_id3");
  
    var temp = Number(freq[i].innerText);
  
    var freq_block = document.getElementsByClassName("block2");
  
    //changing color of freq block
    freq_block[i].style.backgroundColor = "#FF4949";
  
    // To wait for .1 sec
    await new Promise((resolve) =>
      setTimeout(() => {
        resolve();
      }, 2 * delay)
    );
  
    if (temp == 0) {
      //changing color of freq block to previous one
      freq_block[i].style.backgroundColor = "darkgray";
      continue;
    }
  
    var block_label = document.getElementsByClassName("block_id");
  
    //sorting the block array
    for (var j = 0; j < temp; j++) {
      blocks[idx].style.height = `${(i + 1) * 13}px`;
      block_label[idx].innerText = i + 1;
      idx++;
    }
  
    //changing color of freq block to previous one
    freq_block[i].style.backgroundColor = "darkgray";
  
    // To wait for .1 sec
    await new Promise((resolve) =>
      setTimeout(() => {
        resolve();
      }, 2 * delay)
    );
  }
}
  
// Calling generatearray function
generatearray();
  
// Calling generate_freq function
generate_freq();
  
// Calling CountingSort function
CountingSort();

输出：