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"title": "Find All People With Secret",
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"content": "<p>You are given an integer <code>n</code> indicating there are <code>n</code> people numbered from <code>0</code> to <code>n - 1</code>. You are also given a <strong>0-indexed</strong> 2D integer array <code>meetings</code> where <code>meetings[i] = [x<sub>i</sub>, y<sub>i</sub>, time<sub>i</sub>]</code> indicates that person <code>x<sub>i</sub></code> and person <code>y<sub>i</sub></code> have a meeting at <code>time<sub>i</sub></code>. A person may attend <strong>multiple meetings</strong> at the same time. Finally, you are given an integer <code>firstPerson</code>.</p>\n\n<p>Person <code>0</code> has a <strong>secret</strong> and initially shares the secret with a person <code>firstPerson</code> at time <code>0</code>. This secret is then shared every time a meeting takes place with a person that has the secret. More formally, for every meeting, if a person <code>x<sub>i</sub></code> has the secret at <code>time<sub>i</sub></code>, then they will share the secret with person <code>y<sub>i</sub></code>, and vice versa.</p>\n\n<p>The secrets are shared <strong>instantaneously</strong>. That is, a person may receive the secret and share it with people in other meetings within the same time frame.</p>\n\n<p>Return <em>a list of all the people that have the secret after all the meetings have taken place. </em>You may return the answer in <strong>any order</strong>.</p>\n\n<p> </p>\n<p><strong>Example 1:</strong></p>\n\n<pre>\n<strong>Input:</strong> n = 6, meetings = [[1,2,5],[2,3,8],[1,5,10]], firstPerson = 1\n<strong>Output:</strong> [0,1,2,3,5]\n<strong>Explanation:\n</strong>At time 0, person 0 shares the secret with person 1.\nAt time 5, person 1 shares the secret with person 2.\nAt time 8, person 2 shares the secret with person 3.\nAt time 10, person 1 shares the secret with person 5.\nThus, people 0, 1, 2, 3, and 5 know the secret after all the meetings.\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<pre>\n<strong>Input:</strong> n = 4, meetings = [[3,1,3],[1,2,2],[0,3,3]], firstPerson = 3\n<strong>Output:</strong> [0,1,3]\n<strong>Explanation:</strong>\nAt time 0, person 0 shares the secret with person 3.\nAt time 2, neither person 1 nor person 2 know the secret.\nAt time 3, person 3 shares the secret with person 0 and person 1.\nThus, people 0, 1, and 3 know the secret after all the meetings.\n</pre>\n\n<p><strong>Example 3:</strong></p>\n\n<pre>\n<strong>Input:</strong> n = 5, meetings = [[3,4,2],[1,2,1],[2,3,1]], firstPerson = 1\n<strong>Output:</strong> [0,1,2,3,4]\n<strong>Explanation:</strong>\nAt time 0, person 0 shares the secret with person 1.\nAt time 1, person 1 shares the secret with person 2, and person 2 shares the secret with person 3.\nNote that person 2 can share the secret at the same time as receiving it.\nAt time 2, person 3 shares the secret with person 4.\nThus, people 0, 1, 2, 3, and 4 know the secret after all the meetings.\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>2 <= n <= 10<sup>5</sup></code></li>\n\t<li><code>1 <= meetings.length <= 10<sup>5</sup></code></li>\n\t<li><code>meetings[i].length == 3</code></li>\n\t<li><code>0 <= x<sub>i</sub>, y<sub>i </sub><= n - 1</code></li>\n\t<li><code>x<sub>i</sub> != y<sub>i</sub></code></li>\n\t<li><code>1 <= time<sub>i</sub> <= 10<sup>5</sup></code></li>\n\t<li><code>1 <= firstPerson <= n - 1</code></li>\n</ul>\n",
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"code": "class Solution {\npublic:\n vector<int> findAllPeople(int n, vector<vector<int>>& meetings, int firstPerson) {\n \n }\n};",
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"code": "class Solution(object):\n def findAllPeople(self, n, meetings, firstPerson):\n \"\"\"\n :type n: int\n :type meetings: List[List[int]]\n :type firstPerson: int\n :rtype: List[int]\n \"\"\"\n ",
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"code": "\n\n/**\n * Note: The returned array must be malloced, assume caller calls free().\n */\nint* findAllPeople(int n, int** meetings, int meetingsSize, int* meetingsColSize, int firstPerson, int* returnSize){\n\n}",
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"code": "public class Solution {\n public IList<int> FindAllPeople(int n, int[][] meetings, int firstPerson) {\n \n }\n}",
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"code": "/**\n * @param {number} n\n * @param {number[][]} meetings\n * @param {number} firstPerson\n * @return {number[]}\n */\nvar findAllPeople = function(n, meetings, firstPerson) {\n \n};",
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"code": "# @param {Integer} n\n# @param {Integer[][]} meetings\n# @param {Integer} first_person\n# @return {Integer[]}\ndef find_all_people(n, meetings, first_person)\n \nend",
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"lang": "Rust",
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"code": "impl Solution {\n pub fn find_all_people(n: i32, meetings: Vec<Vec<i32>>, first_person: i32) -> Vec<i32> {\n \n }\n}",
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"code": "class Solution {\n\n /**\n * @param Integer $n\n * @param Integer[][] $meetings\n * @param Integer $firstPerson\n * @return Integer[]\n */\n function findAllPeople($n, $meetings, $firstPerson) {\n \n }\n}",
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"code": "function findAllPeople(n: number, meetings: number[][], firstPerson: number): number[] {\n\n};",
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"code": "(define/contract (find-all-people n meetings firstPerson)\n (-> exact-integer? (listof (listof exact-integer?)) exact-integer? (listof exact-integer?))\n\n )",
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"lang": "Erlang",
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"code": "defmodule Solution do\n @spec find_all_people(n :: integer, meetings :: [[integer]], first_person :: integer) :: [integer]\n def find_all_people(n, meetings, first_person) do\n\n end\nend",
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"hints": [
"Could you model all the meetings happening at the same time as a graph?",
"What data structure can you use to efficiently share the secret?",
"You can use the union-find data structure to quickly determine who knows the secret and share the secret."
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