用文字代替数字？ Fisher-Yates 随机化

问题描述

我在这里发现了关于 Fisher-Yates 和随机化的非常有趣的东西：How to randomize (shuffle) a JavaScript array?

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  margin: 1rem 0.5rem;
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<h1>Shuffling</h1>
<p>Comparing the Fisher-Yates to Durstenfield shuffle. Both return randomly sorted numbers quickly and efficiently. Is it O(n)? Only you can tell!</p>
<p>The array to be sorted is 30 numbers,1-30 inclusive. Originally,I intended to do a performance comparison but because of deliberate error introduced into performance.Now() due to Spectre mitigation fixes,that was infeasible to do clientside. So enjoy some shuffled numbers!</p>

<p>Specifically,on pageload each shuffle function will take the input array and return a shuffled result to the DOM.</p>

<div class="results">
  <h2>Results</h2>
  <p>Fisher-Yates: <span id="fyresults"></span></p>
  <p>Durstenfield: <span id="dfresults"></span></p>
</div>

animals = {'Lion':["meet",1.2,'yellow'],'Cat':["milk",0.3,'white'],'dog':["Dog",1,'black']}

def invert_dict(dic):
    return {v: d.setdefault(v,[]).append(k) or d[v] for d in ({},) for k in dic for v in dic[k]}

print(invert_dict(animals))

现在我想用名字替换这 30 位数字（例如：Thomas、Adrian、James、Patrick、Victor...）

我该怎么做？我对此很陌生，我迈出了第一步

解决方法

由于 shuffle 函数会打乱数组索引，因此您可以按照与之前相同的方式打乱数组，但在数组中添加名称字符串。

   
   // replace numbers with names   
const inputArray = ["Thomas","Adrian","James","Patrick","Victor"];

//define Durstenfield shuffle
const durstenShuffle = function(array) {
  for (var i = array.length - 1; i > 0; i--) {
    let j = Math.floor(Math.random() * (i + 1));
    let temp = array[i];
    array[i] = array[j];
    array[j] = temp;
  }
  document.getElementById("dfresults").append(array.toString());
};

//define Fisher-Yates shuffle
const fisherShuffle = function(array) {
  let currentIndex = array.length,temporaryValue,randomIndex;

  while (0 !== currentIndex) {
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }
  document.getElementById("fyresults").append(array.toString());
};

fisherShuffle(inputArray);
durstenShuffle(inputArray);

<div class="results">
  <h2>Results</h2>
  <p>Fisher-Yates: <span id="fyresults"></span></p>
  <p>Durstenfield: <span id="dfresults"></span></p>
</div>

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