{ "data": { "question": { "questionId": "2671", "questionFrontendId": "2608", "boundTopicId": null, "title": "Shortest Cycle in a Graph", "titleSlug": "shortest-cycle-in-a-graph", "content": "

There is a bi-directional graph with n vertices, where each vertex is labeled from 0 to n - 1. The edges in the graph are represented by a given 2D integer array edges, where edges[i] = [ui, vi] denotes an edge between vertex ui and vertex vi. Every vertex pair is connected by at most one edge, and no vertex has an edge to itself.

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Return the length of the shortest cycle in the graph. If no cycle exists, return -1.

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A cycle is a path that starts and ends at the same node, and each edge in the path is used only once.

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Example 1:

\n\"\"\n
\nInput: n = 7, edges = [[0,1],[1,2],[2,0],[3,4],[4,5],[5,6],[6,3]]\nOutput: 3\nExplanation: The cycle with the smallest length is : 0 -> 1 -> 2 -> 0 \n
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Example 2:

\n\"\"\n
\nInput: n = 4, edges = [[0,1],[0,2]]\nOutput: -1\nExplanation: There are no cycles in this graph.\n
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Constraints:

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