number-of-atoms

java

python

python3

mysql

mssql

oraclesql

csharp

javascript

typescript

bash

swift

kotlin

dart

golang

ruby

scala

rust

racket

erlang

elixir

pythondata

postgresql

cangjie

Algorithms

Given a string <code>formula</code> representing a chemical formula, return the count of each atom.

The atomic element always starts with an uppercase character, then zero or more lowercase letters, representing the name.

One or more digits representing that element&#39;s count may follow if the count is greater than <code>1</code>. If the count is <code>1</code>, no digits will follow.

<ul>
	<li>For example, <code>&quot;H2O&quot;</code> and <code>&quot;H2O2&quot;</code> are possible, but <code>&quot;H1O2&quot;</code> is impossible.</li>
</ul>

Two formulas are concatenated together to produce another formula.

<ul>
	<li>For example, <code>&quot;H2O2He3Mg4&quot;</code> is also a formula.</li>
</ul>

A formula placed in parentheses, and a count (optionally added) is also a formula.

<ul>
	<li>For example, <code>&quot;(H2O2)&quot;</code> and <code>&quot;(H2O2)3&quot;</code> are formulas.</li>
</ul>

Return the count of all elements as a string in the following form: the first name (in sorted order), followed by its count (if that count is more than <code>1</code>), followed by the second name (in sorted order), followed by its count (if that count is more than <code>1</code>), and so on.

The test cases are generated so that all the values in the output fit in a 32-bit integer.

&nbsp;
Example 1:

<pre>
Input: formula = &quot;H2O&quot;
Output: &quot;H2O&quot;
Explanation: The count of elements are {&#39;H&#39;: 2, &#39;O&#39;: 1}.
</pre>

Example 2:

<pre>
Input: formula = &quot;Mg(OH)2&quot;
Output: &quot;H2MgO2&quot;
Explanation: The count of elements are {&#39;H&#39;: 2, &#39;Mg&#39;: 1, &#39;O&#39;: 2}.
</pre>

Example 3:

<pre>
Input: formula = &quot;K4(ON(SO3)2)2&quot;
Output: &quot;K4N2O14S4&quot;
Explanation: The count of elements are {&#39;K&#39;: 4, &#39;N&#39;: 2, &#39;O&#39;: 14, &#39;S&#39;: 4}.
</pre>

&nbsp;
Constraints:

<ul>
	<li><code>1 &lt;= formula.length &lt;= 1000</code></li>
	<li><code>formula</code> consists of English letters, digits, <code>&#39;(&#39;</code>, and <code>&#39;)&#39;</code>.</li>
	<li><code>formula</code> is always valid.</li>
</ul>

countOfAtoms

Number of Atoms

Decode String

decode-string

字符串解码

Encode String with Shortest Length

encode-string-with-shortest-length

编码最短长度的字符串

Parse Lisp Expression

parse-lisp-expression

Lisp 语法解析

Stack

Hash Table

String

Sorting

给你一个字符串化学式 <code>formula</code> ，返回 每种原子的数量 。

原子总是以一个大写字母开始，接着跟随 0 个或任意个小写字母，表示原子的名字。

如果数量大于 1，原子后会跟着数字表示原子的数量。如果数量等于 1 则不会跟数字。

<ul>
	<li>例如，<code>"H2O"</code> 和 <code>"H2O2"</code> 是可行的，但 <code>"H1O2"</code> 这个表达是不可行的。</li>
</ul>

两个化学式连在一起可以构成新的化学式。

<ul>
	<li>例如 <code>"H2O2He3Mg4"</code> 也是化学式。</li>
</ul>

由括号括起的化学式并佐以数字（可选择性添加）也是化学式。

<ul>
	<li>例如 <code>"(H2O2)"</code> 和 <code>"(H2O2)3"</code> 是化学式。</li>
</ul>

返回所有原子的数量，格式为：第一个（按字典序）原子的名字，跟着它的数量（如果数量大于 1），然后是第二个原子的名字（按字典序），跟着它的数量（如果数量大于 1），以此类推。

&nbsp;

示例 1：

<pre>
输入：formula = "H2O"
输出："H2O"
解释：原子的数量是 {'H': 2, 'O': 1}。
</pre>

示例 2：

<pre>
输入：formula = "Mg(OH)2"
输出："H2MgO2"
解释：原子的数量是 {'H': 2, 'Mg': 1, 'O': 2}。
</pre>

示例 3：

<pre>
输入：formula = "K4(ON(SO3)2)2"
输出："K4N2O14S4"
解释：原子的数量是 {'K': 4, 'N': 2, 'O': 14, 'S': 4}。
</pre>

&nbsp;

提示：

<ul>
	<li><code>1 &lt;= formula.length&nbsp;&lt;= 1000</code></li>
	<li><code>formula</code> 由英文字母、数字、<code>'('</code> 和 <code>')'</code> 组成</li>
	<li><code>formula</code> 总是有效的化学式</li>
</ul>