number-of-digit-one

java

python

python3

mysql

mssql

oraclesql

csharp

javascript

typescript

bash

swift

kotlin

dart

golang

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rust

racket

erlang

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cangjie

Algorithms

Given an integer <code>n</code>, count the total number of digit <code>1</code> appearing in all non-negative integers less than or equal to <code>n</code>.

&nbsp;
Example 1:

<pre>
Input: n = 13
Output: 6
</pre>

Example 2:

<pre>
Input: n = 0
Output: 0
</pre>

&nbsp;
Constraints:

<ul>
	<li><code>0 &lt;= n &lt;= 109</code></li>
</ul>

countDigitOne

Number of Digit One

Factorial Trailing Zeroes

factorial-trailing-zeroes

阶乘后的零

Digit Count in Range

digit-count-in-range

范围内的数字计数

Recursion

Math

Dynamic Programming

给定一个整数 <code>n</code>，计算所有小于等于 <code>n</code> 的非负整数中数字 <code>1</code> 出现的个数。

&nbsp;

示例 1：

<pre>
输入：n = 13
输出：6
</pre>

示例 2：

<pre>
输入：n = 0
输出：0
</pre>

&nbsp;

提示：

<ul>
	<li><code>0 &lt;= n &lt;= 109</code></li>
</ul>