binary-watch

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Algorithms

A binary watch has 4 LEDs on the top to represent the hours (0-11), and 6 LEDs on the bottom to represent&nbsp;the minutes (0-59). Each LED represents a zero or one, with the least significant bit on the right.

<ul>
	<li>For example, the below binary watch reads <code>&quot;4:51&quot;</code>.</li>
</ul>

<img alt="" src="https://assets.leetcode.com/uploads/2021/04/08/binarywatch.jpg" style="width: 500px; height: 500px;" />

Given an integer <code>turnedOn</code> which represents the number of LEDs that are currently on (ignoring the PM), return all possible times the watch could represent. You may return the answer in any order.

The hour must not contain a leading zero.

<ul>
	<li>For example, <code>&quot;01:00&quot;</code> is not valid. It should be <code>&quot;1:00&quot;</code>.</li>
</ul>

The minute must&nbsp;consist of two digits and may contain a leading zero.

<ul>
	<li>For example, <code>&quot;10:2&quot;</code> is not valid. It should be <code>&quot;10:02&quot;</code>.</li>
</ul>

&nbsp;
Example 1:
<pre>Input: turnedOn = 1
Output: ["0:01","0:02","0:04","0:08","0:16","0:32","1:00","2:00","4:00","8:00"]
</pre>Example 2:
<pre>Input: turnedOn = 9
Output: []
</pre>
&nbsp;
Constraints:

<ul>
	<li><code>0 &lt;= turnedOn &lt;= 10</code></li>
</ul>

readBinaryWatch

Binary Watch

Letter Combinations of a Phone Number

letter-combinations-of-a-phone-number

电话号码的字母组合

Number of 1 Bits

number-of-1-bits

位1的个数

Bit Manipulation

Backtracking

&#20108;&#36827;&#21046;&#25163;&#34920;&#39030;&#37096;&#26377; 4 &#20010; LED &#20195;&#34920; &#23567;&#26102;&#65288;0-11&#65289;&#65292;&#24213;&#37096;&#30340; 6 &#20010; LED &#20195;&#34920; &#20998;&#38047;&#65288;0-59&#65289;&#12290;&#27599;&#20010; LED &#20195;&#34920;&#19968;&#20010; 0 &#25110; 1&#65292;&#26368;&#20302;&#20301;&#22312;&#21491;&#20391;&#12290;

<ul>
	<li>&#20363;&#22914;&#65292;&#19979;&#38754;&#30340;&#20108;&#36827;&#21046;&#25163;&#34920;&#35835;&#21462; <code>"4:51"</code> &#12290;</li>
</ul>

<img src="https://assets.leetcode.com/uploads/2021/04/08/binarywatch.jpg" style="height: 300px; width" />

&#32473;&#20320;&#19968;&#20010;&#25972;&#25968; <code>turnedOn</code> &#65292;&#34920;&#31034;&#24403;&#21069;&#20142;&#30528;&#30340; LED &#30340;&#25968;&#37327;&#65292;&#36820;&#22238;&#20108;&#36827;&#21046;&#25163;&#34920;&#21487;&#20197;&#34920;&#31034;&#30340;&#25152;&#26377;&#21487;&#33021;&#26102;&#38388;&#12290;&#20320;&#21487;&#20197; &#25353;&#20219;&#24847;&#39034;&#24207; &#36820;&#22238;&#31572;&#26696;&#12290;

&#23567;&#26102;&#19981;&#20250;&#20197;&#38646;&#24320;&#22836;&#65306;

<ul>
	<li>&#20363;&#22914;&#65292;<code>"01:00"</code> &#26159;&#26080;&#25928;&#30340;&#26102;&#38388;&#65292;&#27491;&#30830;&#30340;&#20889;&#27861;&#24212;&#35813;&#26159; <code>"1:00"</code> &#12290;</li>
</ul>

&#20998;&#38047;&#24517;&#39035;&#30001;&#20004;&#20301;&#25968;&#32452;&#25104;&#65292;&#21487;&#33021;&#20250;&#20197;&#38646;&#24320;&#22836;&#65306;

<ul>
	<li>&#20363;&#22914;&#65292;<code>"10:2"</code> &#26159;&#26080;&#25928;&#30340;&#26102;&#38388;&#65292;&#27491;&#30830;&#30340;&#20889;&#27861;&#24212;&#35813;&#26159; <code>"10:02"</code> &#12290;</li>
</ul>

&nbsp;

&#31034;&#20363; 1&#65306;

<pre>
&#36755;&#20837;&#65306;turnedOn = 1
&#36755;&#20986;&#65306;["0:01","0:02","0:04","0:08","0:16","0:32","1:00","2:00","4:00","8:00"]
</pre>

&#31034;&#20363; 2&#65306;

<pre>
&#36755;&#20837;&#65306;turnedOn = 9
&#36755;&#20986;&#65306;[]
</pre>

&nbsp;

&#25552;&#31034;&#65306;

<ul>
	<li><code>0 &lt;= turnedOn &lt;= 10</code></li>
</ul>

Sunbelt Computer Software

PL/B Language Development and Support