Project Notes

Bulls and Cows

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Description

tab: English
 
<p>You are playing the <strong><a href="https://en.wikipedia.org/wiki/Bulls_and_Cows" target="_blank">Bulls and Cows</a></strong> game with your friend.</p>
 
<p>You write down a secret number and ask your friend to guess what the number is. When your friend makes a guess, you provide a hint with the following info:</p>
 
<ul>
	<li>The number of &quot;bulls&quot;, which are digits in the guess that are in the correct position.</li>
	<li>The number of &quot;cows&quot;, which are digits in the guess that are in your secret number but are located in the wrong position. Specifically, the non-bull digits in the guess that could be rearranged such that they become bulls.</li>
</ul>
 
<p>Given the secret number <code>secret</code> and your friend&#39;s guess <code>guess</code>, return <em>the hint for your friend&#39;s guess</em>.</p>
 
<p>The hint should be formatted as <code>&quot;xAyB&quot;</code>, where <code>x</code> is the number of bulls and <code>y</code> is the number of cows. Note that both <code>secret</code> and <code>guess</code> may contain duplicate digits.</p>
 
<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
 
<pre>
<strong>Input:</strong> secret = &quot;1807&quot;, guess = &quot;7810&quot;
<strong>Output:</strong> &quot;1A3B&quot;
<strong>Explanation:</strong> Bulls are connected with a &#39;|&#39; and cows are underlined:
&quot;1807&quot;
  |
&quot;<u>7</u>8<u>10</u>&quot;</pre>
 
<p><strong class="example">Example 2:</strong></p>
 
<pre>
<strong>Input:</strong> secret = &quot;1123&quot;, guess = &quot;0111&quot;
<strong>Output:</strong> &quot;1A1B&quot;
<strong>Explanation:</strong> Bulls are connected with a &#39;|&#39; and cows are underlined:
&quot;1123&quot;        &quot;1123&quot;
  |      or     |
&quot;01<u>1</u>1&quot;        &quot;011<u>1</u>&quot;
Note that only one of the two unmatched 1s is counted as a cow since the non-bull digits can only be rearranged to allow one 1 to be a bull.
</pre>
 
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>
 
<ul>
	<li><code>1 &lt;= secret.length, guess.length &lt;= 1000</code></li>
	<li><code>secret.length == guess.length</code></li>
	<li><code>secret</code> and <code>guess</code> consist of digits only.</li>
</ul>
 
 
 
---
 
[submissions](https://leetcode.com/problems/bulls-and-cows/submissions/) | [solutions](https://leetcode.com/problems/bulls-and-cows/solutions/)
 
 
tab: 中文
 
<p>你在和朋友一起玩 <a href="https://baike.baidu.com/item/%E7%8C%9C%E6%95%B0%E5%AD%97/83200?fromtitle=Bulls+and+Cows&amp;fromid=12003488&amp;fr=aladdin" target="_blank">猜数字（Bulls and Cows）</a>游戏，该游戏规则如下：</p>
 
<p>写出一个秘密数字，并请朋友猜这个数字是多少。朋友每猜测一次，你就会给他一个包含下述信息的提示：</p>
 
<ul>
	<li>猜测数字中有多少位属于数字和确切位置都猜对了（称为 "Bulls"，公牛），</li>
	<li>有多少位属于数字猜对了但是位置不对（称为 "Cows"，奶牛）。也就是说，这次猜测中有多少位非公牛数字可以通过重新排列转换成公牛数字。</li>
</ul>
 
<p>给你一个秘密数字&nbsp;<code>secret</code> 和朋友猜测的数字&nbsp;<code>guess</code> ，请你返回对朋友这次猜测的提示。</p>
 
<p>提示的格式为 <code>"xAyB"</code> ，<code>x</code> 是公牛个数， <code>y</code> 是奶牛个数，<code>A</code> 表示公牛，<code>B</code>&nbsp;表示奶牛。</p>
 
<p>请注意秘密数字和朋友猜测的数字都可能含有重复数字。</p>
 
<p>&nbsp;</p>
 
<p><strong>示例 1：</strong></p>
 
<pre>
<strong>输入：</strong>secret = "1807", guess = "7810"
<strong>输出：</strong>"1A3B"
<strong>解释：</strong>数字和位置都对（公牛）用 '|' 连接，数字猜对位置不对（奶牛）的采用斜体加粗标识。
"1807"
  |
"<em><strong>7</strong></em>8<em><strong>10</strong></em>"</pre>
 
<p><strong>示例 2：</strong></p>
 
<pre>
<strong>输入：</strong>secret = "1123", guess = "0111"
<strong>输出：</strong>"1A1B"
<strong>解释：</strong>数字和位置都对（公牛）用 '|' 连接，数字猜对位置不对（奶牛）的采用斜体加粗标识。
"1123"        "1123"
  |      or     |
"01<em><strong>1</strong></em>1"        "011<em><strong>1</strong></em>"
注意，两个不匹配的 1 中，只有一个会算作奶牛（数字猜对位置不对）。通过重新排列非公牛数字，其中仅有一个 1 可以成为公牛数字。</pre>
 
<p>&nbsp;</p>
 
<p><strong>提示：</strong></p>
 
<ul>
	<li><code>1 &lt;= secret.length, guess.length &lt;= 1000</code></li>
	<li><code>secret.length == guess.length</code></li>
	<li><code>secret</code> 和 <code>guess</code> 仅由数字组成</li>
</ul>
 
 
 
---
 
[提交记录](https://leetcode.cn/problems/bulls-and-cows/submissions/) | [题解](https://leetcode.cn/problems/bulls-and-cows/solution/)

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