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            "title": "Count All Possible Routes",
            "titleSlug": "count-all-possible-routes",
            "content": "<p>You are given an array of <strong>distinct</strong> positive integers locations where <code>locations[i]</code> represents the position of city <code>i</code>. You are also given integers <code>start</code>, <code>finish</code> and <code>fuel</code> representing the starting city, ending city, and the initial amount of fuel you have, respectively.</p>\n\n<p>At each step, if you are at city <code>i</code>, you can pick any city <code>j</code> such that <code>j != i</code> and <code>0 &lt;= j &lt; locations.length</code> and move to city <code>j</code>. Moving from city <code>i</code> to city <code>j</code> reduces the amount of fuel you have by <code>|locations[i] - locations[j]|</code>. Please notice that <code>|x|</code> denotes the absolute value of <code>x</code>.</p>\n\n<p>Notice that <code>fuel</code> <strong>cannot</strong> become negative at any point in time, and that you are <strong>allowed</strong> to visit any city more than once (including <code>start</code> and <code>finish</code>).</p>\n\n<p>Return <em>the count of all possible routes from </em><code>start</code> <em>to</em> <code>finish</code>. Since the answer may be too large, return it modulo <code>10<sup>9</sup> + 7</code>.</p>\n\n<p>&nbsp;</p>\n<p><strong>Example 1:</strong></p>\n\n<pre>\n<strong>Input:</strong> locations = [2,3,6,8,4], start = 1, finish = 3, fuel = 5\n<strong>Output:</strong> 4\n<strong>Explanation:</strong> The following are all possible routes, each uses 5 units of fuel:\n1 -&gt; 3\n1 -&gt; 2 -&gt; 3\n1 -&gt; 4 -&gt; 3\n1 -&gt; 4 -&gt; 2 -&gt; 3\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<pre>\n<strong>Input:</strong> locations = [4,3,1], start = 1, finish = 0, fuel = 6\n<strong>Output:</strong> 5\n<strong>Explanation:</strong> The following are all possible routes:\n1 -&gt; 0, used fuel = 1\n1 -&gt; 2 -&gt; 0, used fuel = 5\n1 -&gt; 2 -&gt; 1 -&gt; 0, used fuel = 5\n1 -&gt; 0 -&gt; 1 -&gt; 0, used fuel = 3\n1 -&gt; 0 -&gt; 1 -&gt; 0 -&gt; 1 -&gt; 0, used fuel = 5\n</pre>\n\n<p><strong>Example 3:</strong></p>\n\n<pre>\n<strong>Input:</strong> locations = [5,2,1], start = 0, finish = 2, fuel = 3\n<strong>Output:</strong> 0\n<strong>Explanation:</strong> It is impossible to get from 0 to 2 using only 3 units of fuel since the shortest route needs 4 units of fuel.\n</pre>\n\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>2 &lt;= locations.length &lt;= 100</code></li>\n\t<li><code>1 &lt;= locations[i] &lt;= 10<sup>9</sup></code></li>\n\t<li>All integers in <code>locations</code> are <strong>distinct</strong>.</li>\n\t<li><code>0 &lt;= start, finish &lt; locations.length</code></li>\n\t<li><code>1 &lt;= fuel &lt;= 200</code></li>\n</ul>\n",
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                    "lang": "C++",
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                    "code": "class Solution {\npublic:\n    int countRoutes(vector<int>& locations, int start, int finish, int fuel) {\n        \n    }\n};",
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                    "code": "class Solution {\n    public int countRoutes(int[] locations, int start, int finish, int fuel) {\n        \n    }\n}",
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                    "lang": "Python",
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                    "code": "class Solution(object):\n    def countRoutes(self, locations, start, finish, fuel):\n        \"\"\"\n        :type locations: List[int]\n        :type start: int\n        :type finish: int\n        :type fuel: int\n        :rtype: int\n        \"\"\"\n        ",
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                    "code": "class Solution:\n    def countRoutes(self, locations: List[int], start: int, finish: int, fuel: int) -> int:\n        ",
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                    "lang": "C",
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                    "code": "\n\nint countRoutes(int* locations, int locationsSize, int start, int finish, int fuel){\n\n}",
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                    "lang": "C#",
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                    "code": "public class Solution {\n    public int CountRoutes(int[] locations, int start, int finish, int fuel) {\n        \n    }\n}",
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                    "code": "/**\n * @param {number[]} locations\n * @param {number} start\n * @param {number} finish\n * @param {number} fuel\n * @return {number}\n */\nvar countRoutes = function(locations, start, finish, fuel) {\n    \n};",
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                    "lang": "Ruby",
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                    "code": "# @param {Integer[]} locations\n# @param {Integer} start\n# @param {Integer} finish\n# @param {Integer} fuel\n# @return {Integer}\ndef count_routes(locations, start, finish, fuel)\n    \nend",
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                    "lang": "Swift",
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                    "code": "class Solution {\n    func countRoutes(_ locations: [Int], _ start: Int, _ finish: Int, _ fuel: Int) -> Int {\n        \n    }\n}",
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                    "lang": "Go",
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                    "code": "func countRoutes(locations []int, start int, finish int, fuel int) int {\n    \n}",
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                    "lang": "Scala",
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                    "code": "object Solution {\n    def countRoutes(locations: Array[Int], start: Int, finish: Int, fuel: Int): Int = {\n        \n    }\n}",
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                    "lang": "Kotlin",
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                    "code": "class Solution {\n    fun countRoutes(locations: IntArray, start: Int, finish: Int, fuel: Int): Int {\n        \n    }\n}",
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                    "lang": "Rust",
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                    "code": "impl Solution {\n    pub fn count_routes(locations: Vec<i32>, start: i32, finish: i32, fuel: i32) -> i32 {\n        \n    }\n}",
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                    "code": "class Solution {\n\n    /**\n     * @param Integer[] $locations\n     * @param Integer $start\n     * @param Integer $finish\n     * @param Integer $fuel\n     * @return Integer\n     */\n    function countRoutes($locations, $start, $finish, $fuel) {\n        \n    }\n}",
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                    "lang": "TypeScript",
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                    "code": "function countRoutes(locations: number[], start: number, finish: number, fuel: number): number {\n\n};",
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                    "code": "(define/contract (count-routes locations start finish fuel)\n  (-> (listof exact-integer?) exact-integer? exact-integer? exact-integer? exact-integer?)\n\n  )",
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                    "lang": "Erlang",
                    "langSlug": "erlang",
                    "code": "-spec count_routes(Locations :: [integer()], Start :: integer(), Finish :: integer(), Fuel :: integer()) -> integer().\ncount_routes(Locations, Start, Finish, Fuel) ->\n  .",
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                    "code": "defmodule Solution do\n  @spec count_routes(locations :: [integer], start :: integer, finish :: integer, fuel :: integer) :: integer\n  def count_routes(locations, start, finish, fuel) do\n\n  end\nend",
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            "hints": [
                "Use dynamic programming to solve this problem with each state defined by the city index and fuel left.",
                "Since the array contains distinct integers fuel will always be spent in each move and so there can be no cycles."
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