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48 lines
1.6 KiB
HTML
48 lines
1.6 KiB
HTML
<p>In a town, there are <code>n</code> people labeled from <code>1</code> to <code>n</code>. There is a rumor that one of these people is secretly the town judge.</p>
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<p>If the town judge exists, then:</p>
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<ol>
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<li>The town judge trusts nobody.</li>
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<li>Everybody (except for the town judge) trusts the town judge.</li>
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<li>There is exactly one person that satisfies properties <strong>1</strong> and <strong>2</strong>.</li>
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</ol>
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<p>You are given an array <code>trust</code> where <code>trust[i] = [a<sub>i</sub>, b<sub>i</sub>]</code> representing that the person labeled <code>a<sub>i</sub></code> trusts the person labeled <code>b<sub>i</sub></code>.</p>
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<p>Return <em>the label of the town judge if the town judge exists and can be identified, or return </em><code>-1</code><em> otherwise</em>.</p>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<pre>
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<strong>Input:</strong> n = 2, trust = [[1,2]]
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<strong>Output:</strong> 2
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</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> n = 3, trust = [[1,3],[2,3]]
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<strong>Output:</strong> 3
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</pre>
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<p><strong>Example 3:</strong></p>
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<pre>
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<strong>Input:</strong> n = 3, trust = [[1,3],[2,3],[3,1]]
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<strong>Output:</strong> -1
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>1 <= n <= 1000</code></li>
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<li><code>0 <= trust.length <= 10<sup>4</sup></code></li>
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<li><code>trust[i].length == 2</code></li>
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<li>All the pairs of <code>trust</code> are <strong>unique</strong>.</li>
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<li><code>a<sub>i</sub> != b<sub>i</sub></code></li>
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<li><code>1 <= a<sub>i</sub>, b<sub>i</sub> <= n</code></li>
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</ul>
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