297 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			297 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| ---
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| id: 5900f3cc1000cf542c50fedf
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| title: '问题 96:数独'
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| challengeType: 5
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| forumTopicId: 302213
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| dashedName: problem-96-su-doku
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| ---
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| 
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| # --description--
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| 
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| 数独(日语含义为*数字位置*)是一个非常流行的解密游戏。 它的起源尚不清楚,但必须归功于莱昂哈德·欧拉(Leonhard Euler),他发明了一种类似的,但更加困难的解密游戏,名叫拉丁方块(Latin Squares)。 数独的目标是用数字替换 9X9 网格中的空白(或零),使得每行,每列和每个 3X3 小网格中都只包含 1 到 9 这 9 个数字。 下面是一个示例,包含一个经典的谜题及其对应解。
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| 
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| <div style="margin: auto; background-color: white; padding: 10px; width: 80%; text-align: center;">
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|   <table border="0" cellpadding="0" cellspacing="0" align="center">
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|     <tbody>
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|       <tr>
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|         <td>
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|           <table cellpadding="5" cellspacing="0" border="1">
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|             <tbody>
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|               <tr>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   0 0 3<br />9 0 0<br />0 0 1
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   0 2 0<br />3 0 5<br />8 0 6
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   6 0 0<br />0 0 1<br />4 0 0
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|                 </td>
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|               </tr>
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|               <tr>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   0 0 8<br />7 0 0<br />0 0 6
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   1 0 2<br />0 0 0<br />7 0 8
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   9 0 0<br />0 0 8<br />2 0 0
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|                 </td>
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|               </tr>
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|               <tr>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   0 0 2<br />8 0 0<br />0 0 5
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   6 0 9<br />2 0 3<br />0 1 0
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   5 0 0<br />0 0 9<br />3 0 0
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|                 </td>
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|               </tr>
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|             </tbody>
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|           </table>
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|         </td>
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|         <td width="50">
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|           <img src="images/spacer.gif" width="50" height="1" alt="" /><br />
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|         </td>
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|         <td>
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|           <table cellpadding="5" cellspacing="0" border="1">
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|             <tbody>
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|               <tr>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   4 8 3<br />9 6 7<br />2 5 1
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   9 2 1<br />3 4 5<br />8 7 6
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   6 5 7<br />8 2 1<br />4 9 3
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|                 </td>
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|               </tr>
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|               <tr>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   5 4 8<br />7 2 9<br />1 3 6
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   1 3 2<br />5 6 4<br />7 9 8
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   9 7 6<br />1 3 8<br />2 4 5
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|                 </td>
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|               </tr>
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|               <tr>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   3 7 2<br />8 1 4<br />6 9 5
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   6 8 9<br />2 5 3<br />4 1 7
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|                 </td>
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|                 <td style="font-family:'courier new';font-size:14pt; color: black; padding: 5px; border: 2px solid black;">
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|                   5 1 4<br />7 6 9<br />3 8 2
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|                 </td>
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|               </tr>
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|             </tbody>
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|           </table>
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|         </td>
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|       </tr>
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|     </tbody>
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|   </table>
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| </div>
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| 
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| 一个构造良好的数独谜题应该只有一个唯一的解,可以通过逻辑解出,虽然可能需要采用“猜测和测试”方法来排除选项(对此有很多争议的意见)。 搜索的复杂性决定了谜题的难度;上面的示例很简单,因此可以通过直接的逻辑推理来解出答案。
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| 
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| `puzzlesArr` 数组里有若干个数独谜题字符串,难度不一,但是每个谜题的解都是唯一的。
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| 
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| 通过解出 `puzzlesArr` 数组中所有谜题,返回所有解左上角三位数字之和;举个例子,483 就是上述例子中左上角的三位数字。
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| 
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| # --hints--
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| 
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| `suDoku(testPuzzles1)` 应该返回一个数字。
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| 
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| ```js
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| assert(typeof suDoku(_testPuzzles1) === 'number');
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| ```
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| 
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| `suDoku(testPuzzles1)` 应该返回 `1190`。
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| 
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| ```js
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| assert.strictEqual(suDoku(_testPuzzles1), 1190);
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| ```
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| 
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| `suDoku(testPuzzles2)` 应该返回 `24702`。
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| 
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| ```js
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| assert.strictEqual(suDoku(_testPuzzles2), 24702);
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| ```
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| 
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| # --seed--
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| 
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| ## --after-user-code--
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| 
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| ```js
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| const _testPuzzles1 = [
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|   '003020600900305001001806400008102900700000008006708200002609500800203009005010300',
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|   '200080300060070084030500209000105408000000000402706000301007040720040060004010003',
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|   '000000907000420180000705026100904000050000040000507009920108000034059000507000000'
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| ];
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| 
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| const _testPuzzles2 = [
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|   '003020600900305001001806400008102900700000008006708200002609500800203009005010300',
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|   '200080300060070084030500209000105408000000000402706000301007040720040060004010003',
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|   '000000907000420180000705026100904000050000040000507009920108000034059000507000000',
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|   '030050040008010500460000012070502080000603000040109030250000098001020600080060020',
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|   '020810740700003100090002805009040087400208003160030200302700060005600008076051090',
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|   '100920000524010000000000070050008102000000000402700090060000000000030945000071006',
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|   '043080250600000000000001094900004070000608000010200003820500000000000005034090710',
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|   '480006902002008001900370060840010200003704100001060049020085007700900600609200018',
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|   '000900002050123400030000160908000000070000090000000205091000050007439020400007000',
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|   '001900003900700160030005007050000009004302600200000070600100030042007006500006800',
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|   '000125400008400000420800000030000095060902010510000060000003049000007200001298000',
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|   '062340750100005600570000040000094800400000006005830000030000091006400007059083260',
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|   '300000000005009000200504000020000700160000058704310600000890100000067080000005437',
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|   '630000000000500008005674000000020000003401020000000345000007004080300902947100080',
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|   '000020040008035000000070602031046970200000000000501203049000730000000010800004000',
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|   '361025900080960010400000057008000471000603000259000800740000005020018060005470329',
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|   '050807020600010090702540006070020301504000908103080070900076205060090003080103040',
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|   '080005000000003457000070809060400903007010500408007020901020000842300000000100080',
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|   '003502900000040000106000305900251008070408030800763001308000104000020000005104800',
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|   '000000000009805100051907420290401065000000000140508093026709580005103600000000000',
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|   '020030090000907000900208005004806500607000208003102900800605007000309000030020050',
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|   '005000006070009020000500107804150000000803000000092805907006000030400010200000600',
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|   '040000050001943600009000300600050002103000506800020007005000200002436700030000040',
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|   '004000000000030002390700080400009001209801307600200008010008053900040000000000800',
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|   '360020089000361000000000000803000602400603007607000108000000000000418000970030014',
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|   '500400060009000800640020000000001008208000501700500000000090084003000600060003002',
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|   '007256400400000005010030060000508000008060200000107000030070090200000004006312700',
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|   '000000000079050180800000007007306800450708096003502700700000005016030420000000000',
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|   '030000080009000500007509200700105008020090030900402001004207100002000800070000090',
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|   '200170603050000100000006079000040700000801000009050000310400000005000060906037002',
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|   '000000080800701040040020030374000900000030000005000321010060050050802006080000000',
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|   '000000085000210009960080100500800016000000000890006007009070052300054000480000000',
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|   '608070502050608070002000300500090006040302050800050003005000200010704090409060701',
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|   '050010040107000602000905000208030501040070020901080406000401000304000709020060010',
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|   '053000790009753400100000002090080010000907000080030070500000003007641200061000940',
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|   '006080300049070250000405000600317004007000800100826009000702000075040190003090600',
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|   '005080700700204005320000084060105040008000500070803010450000091600508007003010600',
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|   '000900800128006400070800060800430007500000009600079008090004010003600284001007000',
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|   '000080000270000054095000810009806400020403060006905100017000620460000038000090000',
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|   '000602000400050001085010620038206710000000000019407350026040530900020007000809000',
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|   '000900002050123400030000160908000000070000090000000205091000050007439020400007000',
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|   '380000000000400785009020300060090000800302009000040070001070500495006000000000092',
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|   '000158000002060800030000040027030510000000000046080790050000080004070100000325000',
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|   '010500200900001000002008030500030007008000500600080004040100700000700006003004050',
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|   '080000040000469000400000007005904600070608030008502100900000005000781000060000010',
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|   '904200007010000000000706500000800090020904060040002000001607000000000030300005702',
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|   '000700800006000031040002000024070000010030080000060290000800070860000500002006000',
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|   '001007090590080001030000080000005800050060020004100000080000030100020079020700400',
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|   '000003017015009008060000000100007000009000200000500004000000020500600340340200000',
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|   '300200000000107000706030500070009080900020004010800050009040301000702000000008006'
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| ];
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| ```
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| 
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| ## --seed-contents--
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| 
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| ```js
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| function suDoku(puzzlesArr) {
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| 
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|   return true;
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| }
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| 
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| // Only change code above this line
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| 
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| const testPuzzles1 = [
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|   '003020600900305001001806400008102900700000008006708200002609500800203009005010300',
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|   '200080300060070084030500209000105408000000000402706000301007040720040060004010003',
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|   '000000907000420180000705026100904000050000040000507009920108000034059000507000000'
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| ];
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| 
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| suDoku(testPuzzles1);
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| ```
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| 
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| # --solutions--
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| 
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| ```js
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| function suDoku(puzzlesArr) {
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|   function solve(puzzle) {
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|     for (let row = 0; row < 9; row++) {
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|       for (let col = 0; col < 9; col++) {
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|         if (puzzle[row][col] > 0) {
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|           continue;
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|         }
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| 
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|         const allowedNumbers = getAllowedNumbers(puzzle, row, col);
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| 
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|         for (let number = 1; number <= 9; number++) {
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|           if (allowedNumbers[number]) {
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|             puzzle[row][col] = number;
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|             if (solve(puzzle)) {
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|               return true;
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|             }
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|           }
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|         }
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| 
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|         puzzle[row][col] = 0;
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|         return false;
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|       }
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|     }
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|     return true;
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|   }
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| 
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|   function getAllowedNumbers(puzzle, row, col) {
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|     const allowed = new Array(10).fill(true);
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|     allowed[0] = false;
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| 
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|     for (let i = 0; i < 9; i++) {
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|       const numberInSameRow = puzzle[row][i];
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|       if (numberInSameRow > 0) {
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|         allowed[numberInSameRow] = false;
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|       }
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| 
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|       const numberInSameCol = puzzle[i][col];
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|       if (numberInSameCol > 0) {
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|         allowed[numberInSameCol] = false;
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|       }
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|     }
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| 
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|     const rowOfSubGrid = Math.floor(row / 3) * 3;
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|     const colOfSubGrid = Math.floor(col / 3) * 3;
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|     for (let rowInSubGrid = 0; rowInSubGrid < 3; rowInSubGrid++) {
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|       for (let colInSubGrid = 0; colInSubGrid < 3; colInSubGrid++) {
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|         const numberInSameSubGrid =
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|           puzzle[rowOfSubGrid + rowInSubGrid][colOfSubGrid + colInSubGrid];
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|         if (numberInSameSubGrid > 0) {
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|           allowed[numberInSameSubGrid] = false;
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|         }
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|       }
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|     }
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| 
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|     return allowed;
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|   }
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| 
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|   function parsePuzzle(string) {
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|     const puzzle = [];
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|     for (let row = 0; row < 9; row++) {
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|       puzzle.push(
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|         string
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|           .slice(row * 9, 9 + row * 9)
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|           .split('')
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|           .map(x => parseInt(x, 10))
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|       );
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|     }
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|     return puzzle;
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|   }
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| 
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|   let sum = 0;
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|   for (let i = 0; i < puzzlesArr.length; i++) {
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|     const puzzle = parsePuzzle(puzzlesArr[i]);
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|     if (solve(puzzle)) {
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|       sum += 100 * puzzle[0][0] + 10 * puzzle[0][1] + puzzle[0][2];
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|     }
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|   }
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| 
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|   return sum;
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| }
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| ```
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