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44 lines
2.3 KiB
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<p>There is an <strong>undirected</strong> graph consisting of <code>n</code> nodes numbered from <code>1</code> to <code>n</code>. You are given the integer <code>n</code> and a <strong>2D</strong> array <code>edges</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>. The graph can be disconnected.</p>
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<p>You can add <strong>at most</strong> two additional edges (possibly none) to this graph so that there are no repeated edges and no self-loops.</p>
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<p>Return <code>true</code><em> if it is possible to make the degree of each node in the graph even, otherwise return </em><code>false</code><em>.</em></p>
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<p>The degree of a node is the number of edges connected to it.</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/2022/10/26/agraphdrawio.png" style="width: 500px; height: 190px;" />
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<pre>
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<strong>Input:</strong> n = 5, edges = [[1,2],[2,3],[3,4],[4,2],[1,4],[2,5]]
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<strong>Output:</strong> true
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<strong>Explanation:</strong> The above diagram shows a valid way of adding an edge.
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Every node in the resulting graph is connected to an even number of edges.
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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/2022/10/26/aagraphdrawio.png" style="width: 400px; height: 120px;" />
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<pre>
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<strong>Input:</strong> n = 4, edges = [[1,2],[3,4]]
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<strong>Output:</strong> true
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<strong>Explanation:</strong> The above diagram shows a valid way of adding two edges.</pre>
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<p><strong>Example 3:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2022/10/26/aaagraphdrawio.png" style="width: 150px; height: 158px;" />
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<pre>
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<strong>Input:</strong> n = 4, edges = [[1,2],[1,3],[1,4]]
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<strong>Output:</strong> false
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<strong>Explanation:</strong> It is not possible to obtain a valid graph with adding at most 2 edges.</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>3 <= n <= 10<sup>5</sup></code></li>
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<li><code>2 <= edges.length <= 10<sup>5</sup></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> <= n</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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</ul>
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