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            "title": "Random Pick with Weight",
            "titleSlug": "random-pick-with-weight",
            "content": "<p>You are given a <strong>0-indexed</strong> array of positive integers <code>w</code> where <code>w[i]</code> describes the <strong>weight</strong> of the <code>i<sup>th</sup></code> index.</p>\n\n<p>You need to implement the function <code>pickIndex()</code>, which <strong>randomly</strong> picks an index in the range <code>[0, w.length - 1]</code> (<strong>inclusive</strong>) and returns it. The <strong>probability</strong> of picking an index <code>i</code> is <code>w[i] / sum(w)</code>.</p>\n\n<ul>\n\t<li>For example, if <code>w = [1, 3]</code>, the probability of picking index <code>0</code> is <code>1 / (1 + 3) = 0.25</code> (i.e., <code>25%</code>), and the probability of picking index <code>1</code> is <code>3 / (1 + 3) = 0.75</code> (i.e., <code>75%</code>).</li>\n</ul>\n\n<p>&nbsp;</p>\n<p><strong class=\"example\">Example 1:</strong></p>\n\n<pre>\n<strong>Input</strong>\n[&quot;Solution&quot;,&quot;pickIndex&quot;]\n[[[1]],[]]\n<strong>Output</strong>\n[null,0]\n\n<strong>Explanation</strong>\nSolution solution = new Solution([1]);\nsolution.pickIndex(); // return 0. The only option is to return 0 since there is only one element in w.\n</pre>\n\n<p><strong class=\"example\">Example 2:</strong></p>\n\n<pre>\n<strong>Input</strong>\n[&quot;Solution&quot;,&quot;pickIndex&quot;,&quot;pickIndex&quot;,&quot;pickIndex&quot;,&quot;pickIndex&quot;,&quot;pickIndex&quot;]\n[[[1,3]],[],[],[],[],[]]\n<strong>Output</strong>\n[null,1,1,1,1,0]\n\n<strong>Explanation</strong>\nSolution solution = new Solution([1, 3]);\nsolution.pickIndex(); // return 1. It is returning the second element (index = 1) that has a probability of 3/4.\nsolution.pickIndex(); // return 1\nsolution.pickIndex(); // return 1\nsolution.pickIndex(); // return 1\nsolution.pickIndex(); // return 0. It is returning the first element (index = 0) that has a probability of 1/4.\n\nSince this is a randomization problem, multiple answers are allowed.\nAll of the following outputs can be considered correct:\n[null,1,1,1,1,0]\n[null,1,1,1,1,1]\n[null,1,1,1,0,0]\n[null,1,1,1,0,1]\n[null,1,0,1,0,0]\n......\nand so on.\n</pre>\n\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>1 &lt;= w.length &lt;= 10<sup>4</sup></code></li>\n\t<li><code>1 &lt;= w[i] &lt;= 10<sup>5</sup></code></li>\n\t<li><code>pickIndex</code> will be called at most <code>10<sup>4</sup></code> times.</li>\n</ul>\n",
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            "difficulty": "Medium",
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                    "code": "class Solution {\npublic:\n    Solution(vector<int>& w) {\n        \n    }\n    \n    int pickIndex() {\n        \n    }\n};\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution* obj = new Solution(w);\n * int param_1 = obj->pickIndex();\n */",
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                    "code": "class Solution {\n\n    public Solution(int[] w) {\n        \n    }\n    \n    public int pickIndex() {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution obj = new Solution(w);\n * int param_1 = obj.pickIndex();\n */",
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                    "lang": "Python",
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                    "code": "class Solution(object):\n\n    def __init__(self, w):\n        \"\"\"\n        :type w: List[int]\n        \"\"\"\n        \n\n    def pickIndex(self):\n        \"\"\"\n        :rtype: int\n        \"\"\"\n        \n\n\n# Your Solution object will be instantiated and called as such:\n# obj = Solution(w)\n# param_1 = obj.pickIndex()",
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                    "code": "class Solution:\n\n    def __init__(self, w: List[int]):\n        \n\n    def pickIndex(self) -> int:\n        \n\n\n# Your Solution object will be instantiated and called as such:\n# obj = Solution(w)\n# param_1 = obj.pickIndex()",
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                    "lang": "C",
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                    "code": "\n\n\ntypedef struct {\n    \n} Solution;\n\n\nSolution* solutionCreate(int* w, int wSize) {\n    \n}\n\nint solutionPickIndex(Solution* obj) {\n    \n}\n\nvoid solutionFree(Solution* obj) {\n    \n}\n\n/**\n * Your Solution struct will be instantiated and called as such:\n * Solution* obj = solutionCreate(w, wSize);\n * int param_1 = solutionPickIndex(obj);\n \n * solutionFree(obj);\n*/",
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                    "code": "public class Solution {\n\n    public Solution(int[] w) {\n        \n    }\n    \n    public int PickIndex() {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution obj = new Solution(w);\n * int param_1 = obj.PickIndex();\n */",
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                    "code": "/**\n * @param {number[]} w\n */\nvar Solution = function(w) {\n    \n};\n\n/**\n * @return {number}\n */\nSolution.prototype.pickIndex = function() {\n    \n};\n\n/** \n * Your Solution object will be instantiated and called as such:\n * var obj = new Solution(w)\n * var param_1 = obj.pickIndex()\n */",
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                    "lang": "TypeScript",
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                    "code": "class Solution {\n    constructor(w: number[]) {\n        \n    }\n\n    pickIndex(): number {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * var obj = new Solution(w)\n * var param_1 = obj.pickIndex()\n */",
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                    "lang": "PHP",
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                    "code": "class Solution {\n    /**\n     * @param Integer[] $w\n     */\n    function __construct($w) {\n        \n    }\n  \n    /**\n     * @return Integer\n     */\n    function pickIndex() {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * $obj = Solution($w);\n * $ret_1 = $obj->pickIndex();\n */",
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                    "lang": "Swift",
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                    "code": "\nclass Solution {\n\n    init(_ w: [Int]) {\n        \n    }\n    \n    func pickIndex() -> Int {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * let obj = Solution(w)\n * let ret_1: Int = obj.pickIndex()\n */",
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                    "lang": "Kotlin",
                    "langSlug": "kotlin",
                    "code": "class Solution(w: IntArray) {\n\n    fun pickIndex(): Int {\n        \n    }\n\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * var obj = Solution(w)\n * var param_1 = obj.pickIndex()\n */",
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                    "code": "class Solution {\n\n  Solution(List<int> w) {\n    \n  }\n  \n  int pickIndex() {\n    \n  }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution obj = Solution(w);\n * int param1 = obj.pickIndex();\n */",
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                    "lang": "Go",
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                    "code": "type Solution struct {\n    \n}\n\n\nfunc Constructor(w []int) Solution {\n    \n}\n\n\nfunc (this *Solution) PickIndex() int {\n    \n}\n\n\n/**\n * Your Solution object will be instantiated and called as such:\n * obj := Constructor(w);\n * param_1 := obj.PickIndex();\n */",
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                    "code": "class Solution\n\n=begin\n    :type w: Integer[]\n=end\n    def initialize(w)\n        \n    end\n\n\n=begin\n    :rtype: Integer\n=end\n    def pick_index()\n        \n    end\n\n\nend\n\n# Your Solution object will be instantiated and called as such:\n# obj = Solution.new(w)\n# param_1 = obj.pick_index()",
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                    "lang": "Scala",
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                    "code": "class Solution(_w: Array[Int]) {\n\n    def pickIndex(): Int = {\n        \n    }\n\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * var obj = new Solution(w)\n * var param_1 = obj.pickIndex()\n */",
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                    "code": "struct Solution {\n\n}\n\n\n/** \n * `&self` means the method takes an immutable reference.\n * If you need a mutable reference, change it to `&mut self` instead.\n */\nimpl Solution {\n\n    fn new(w: Vec<i32>) -> Self {\n        \n    }\n    \n    fn pick_index(&self) -> i32 {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * let obj = Solution::new(w);\n * let ret_1: i32 = obj.pick_index();\n */",
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