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34 lines
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34 lines
1.8 KiB
HTML
<p>In this problem, a tree is an <strong>undirected graph</strong> that is connected and has no cycles.</p>
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<p>You are given a graph that started as a tree with <code>n</code> nodes labeled from <code>1</code> to <code>n</code>, with one additional edge added. The added edge has two <strong>different</strong> vertices chosen from <code>1</code> to <code>n</code>, and was not an edge that already existed. The graph is represented as an array <code>edges</code> of length <code>n</code> where <code>edges[i] = [a<sub>i</sub>, b<sub>i</sub>]</code> indicates that there is an edge between nodes <code>a<sub>i</sub></code> and <code>b<sub>i</sub></code> in the graph.</p>
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<p>Return <em>an edge that can be removed so that the resulting graph is a tree of </em><code>n</code><em> nodes</em>. If there are multiple answers, return the answer that occurs last in the input.</p>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2021/05/02/reduntant1-1-graph.jpg" style="width: 222px; height: 222px;" />
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<pre>
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<strong>Input:</strong> edges = [[1,2],[1,3],[2,3]]
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<strong>Output:</strong> [2,3]
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</pre>
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<p><strong>Example 2:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2021/05/02/reduntant1-2-graph.jpg" style="width: 382px; height: 222px;" />
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<pre>
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<strong>Input:</strong> edges = [[1,2],[2,3],[3,4],[1,4],[1,5]]
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<strong>Output:</strong> [1,4]
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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>n == edges.length</code></li>
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<li><code>3 <= n <= 1000</code></li>
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<li><code>edges[i].length == 2</code></li>
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<li><code>1 <= a<sub>i</sub> < b<sub>i</sub> <= edges.length</code></li>
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<li><code>a<sub>i</sub> != b<sub>i</sub></code></li>
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<li>There are no repeated edges.</li>
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<li>The given graph is connected.</li>
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</ul>
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