{ "data": { "question": { "questionId": "2403", "questionFrontendId": "2316", "boundTopicId": null, "title": "Count Unreachable Pairs of Nodes in an Undirected Graph", "titleSlug": "count-unreachable-pairs-of-nodes-in-an-undirected-graph", "content": "

You are given an integer n. There is an undirected graph with n nodes, numbered from 0 to n - 1. You are given a 2D integer array edges where edges[i] = [ai, bi] denotes that there exists an undirected edge connecting nodes ai and bi.

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Return the number of pairs of different nodes that are unreachable from each other.

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Example 1:

\n\"\"\n
\nInput: n = 3, edges = [[0,1],[0,2],[1,2]]\nOutput: 0\nExplanation: There are no pairs of nodes that are unreachable from each other. Therefore, we return 0.\n
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Example 2:

\n\"\"\n
\nInput: n = 7, edges = [[0,2],[0,5],[2,4],[1,6],[5,4]]\nOutput: 14\nExplanation: There are 14 pairs of nodes that are unreachable from each other:\n[[0,1],[0,3],[0,6],[1,2],[1,3],[1,4],[1,5],[2,3],[2,6],[3,4],[3,5],[3,6],[4,6],[5,6]].\nTherefore, we return 14.\n
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Constraints:

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