{ "data": { "question": { "questionId": "2803", "questionFrontendId": "2699", "boundTopicId": null, "title": "Modify Graph Edge Weights", "titleSlug": "modify-graph-edge-weights", "content": "

You are given an undirected weighted connected graph containing n nodes labeled from 0 to n - 1, and an integer array edges where edges[i] = [ai, bi, wi] indicates that there is an edge between nodes ai and bi with weight wi.

\n\n

Some edges have a weight of -1 (wi = -1), while others have a positive weight (wi > 0).

\n\n

Your task is to modify all edges with a weight of -1 by assigning them positive integer values in the range [1, 2 * 109] so that the shortest distance between the nodes source and destination becomes equal to an integer target. If there are multiple modifications that make the shortest distance between source and destination equal to target, any of them will be considered correct.

\n\n

Return an array containing all edges (even unmodified ones) in any order if it is possible to make the shortest distance from source to destination equal to target, or an empty array if it's impossible.

\n\n

Note: You are not allowed to modify the weights of edges with initial positive weights.

\n\n

 

\n

Example 1:

\n\n

\"\"

\n\n
\nInput: n = 5, edges = [[4,1,-1],[2,0,-1],[0,3,-1],[4,3,-1]], source = 0, destination = 1, target = 5\nOutput: [[4,1,1],[2,0,1],[0,3,3],[4,3,1]]\nExplanation: The graph above shows a possible modification to the edges, making the distance from 0 to 1 equal to 5.\n
\n\n

Example 2:

\n\n

\"\"

\n\n
\nInput: n = 3, edges = [[0,1,-1],[0,2,5]], source = 0, destination = 2, target = 6\nOutput: []\nExplanation: The graph above contains the initial edges. It is not possible to make the distance from 0 to 2 equal to 6 by modifying the edge with weight -1. So, an empty array is returned.\n
\n\n

Example 3:

\n\n

\"\"

\n\n
\nInput: n = 4, edges = [[1,0,4],[1,2,3],[2,3,5],[0,3,-1]], source = 0, destination = 2, target = 6\nOutput: [[1,0,4],[1,2,3],[2,3,5],[0,3,1]]\nExplanation: The graph above shows a modified graph having the shortest distance from 0 to 2 as 6.\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": null, "translatedContent": null, "isPaidOnly": false, "difficulty": "Hard", "likes": 255, "dislikes": 43, "isLiked": null, "similarQuestions": "[]", "exampleTestcases": "5\n[[4,1,-1],[2,0,-1],[0,3,-1],[4,3,-1]]\n0\n1\n5\n3\n[[0,1,-1],[0,2,5]]\n0\n2\n6\n4\n[[1,0,4],[1,2,3],[2,3,5],[0,3,-1]]\n0\n2\n6", "categoryTitle": "Algorithms", "contributors": [], "topicTags": [ { "name": "Graph", "slug": "graph", "translatedName": null, "__typename": "TopicTagNode" }, { "name": "Heap (Priority Queue)", "slug": "heap-priority-queue", "translatedName": null, "__typename": "TopicTagNode" }, { "name": "Shortest Path", "slug": "shortest-path", "translatedName": null, "__typename": "TopicTagNode" } ], "companyTagStats": null, "codeSnippets": [ { "lang": "C++", "langSlug": "cpp", "code": "class Solution {\npublic:\n vector> modifiedGraphEdges(int n, vector>& edges, int source, int destination, int target) {\n \n }\n};", "__typename": "CodeSnippetNode" }, { "lang": "Java", "langSlug": "java", "code": "class Solution {\n public int[][] modifiedGraphEdges(int n, int[][] edges, int source, int destination, int target) {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Python", "langSlug": "python", "code": "class Solution(object):\n def modifiedGraphEdges(self, n, edges, source, destination, target):\n \"\"\"\n :type n: int\n :type edges: List[List[int]]\n :type source: int\n :type destination: int\n :type target: int\n :rtype: List[List[int]]\n \"\"\"\n ", "__typename": "CodeSnippetNode" }, { "lang": "Python3", "langSlug": "python3", "code": "class Solution:\n def modifiedGraphEdges(self, n: int, edges: List[List[int]], source: int, destination: int, target: int) -> List[List[int]]:\n ", "__typename": "CodeSnippetNode" }, { "lang": "C", "langSlug": "c", "code": "/**\n * Return an array of arrays of size *returnSize.\n * The sizes of the arrays are returned as *returnColumnSizes array.\n * Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().\n */\nint** modifiedGraphEdges(int n, int** edges, int edgesSize, int* edgesColSize, int source, int destination, int target, int* returnSize, int** returnColumnSizes){\n\n}", "__typename": "CodeSnippetNode" }, { "lang": "C#", "langSlug": "csharp", "code": "public class Solution {\n public int[][] ModifiedGraphEdges(int n, int[][] edges, int source, int destination, int target) {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "JavaScript", "langSlug": "javascript", "code": "/**\n * @param {number} n\n * @param {number[][]} edges\n * @param {number} source\n * @param {number} destination\n * @param {number} target\n * @return {number[][]}\n */\nvar modifiedGraphEdges = function(n, edges, source, destination, target) {\n \n};", "__typename": "CodeSnippetNode" }, { "lang": "TypeScript", "langSlug": "typescript", "code": "function modifiedGraphEdges(n: number, edges: number[][], source: number, destination: number, target: number): number[][] {\n\n};", "__typename": "CodeSnippetNode" }, { "lang": "PHP", "langSlug": "php", "code": "class Solution {\n\n /**\n * @param Integer $n\n * @param Integer[][] $edges\n * @param Integer $source\n * @param Integer $destination\n * @param Integer $target\n * @return Integer[][]\n */\n function modifiedGraphEdges($n, $edges, $source, $destination, $target) {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Swift", "langSlug": "swift", "code": "class Solution {\n func modifiedGraphEdges(_ n: Int, _ edges: [[Int]], _ source: Int, _ destination: Int, _ target: Int) -> [[Int]] {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Kotlin", "langSlug": "kotlin", "code": "class Solution {\n fun modifiedGraphEdges(n: Int, edges: Array, source: Int, destination: Int, target: Int): Array {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Dart", "langSlug": "dart", "code": "class Solution {\n List> modifiedGraphEdges(int n, List> edges, int source, int destination, int target) {\n\n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Go", "langSlug": "golang", "code": "func modifiedGraphEdges(n int, edges [][]int, source int, destination int, target int) [][]int {\n \n}", "__typename": "CodeSnippetNode" }, { "lang": "Ruby", "langSlug": "ruby", "code": "# @param {Integer} n\n# @param {Integer[][]} edges\n# @param {Integer} source\n# @param {Integer} destination\n# @param {Integer} target\n# @return {Integer[][]}\ndef modified_graph_edges(n, edges, source, destination, target)\n \nend", "__typename": "CodeSnippetNode" }, { "lang": "Scala", "langSlug": "scala", "code": "object Solution {\n def modifiedGraphEdges(n: Int, edges: Array[Array[Int]], source: Int, destination: Int, target: Int): Array[Array[Int]] = {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Rust", "langSlug": "rust", "code": "impl Solution {\n pub fn modified_graph_edges(n: i32, edges: Vec>, source: i32, destination: i32, target: i32) -> Vec> {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Racket", "langSlug": "racket", "code": "(define/contract (modified-graph-edges n edges source destination target)\n (-> exact-integer? (listof (listof exact-integer?)) exact-integer? exact-integer? exact-integer? (listof (listof exact-integer?)))\n\n )", "__typename": "CodeSnippetNode" }, { "lang": "Erlang", "langSlug": "erlang", "code": "-spec modified_graph_edges(N :: integer(), Edges :: [[integer()]], Source :: integer(), Destination :: integer(), Target :: integer()) -> [[integer()]].\nmodified_graph_edges(N, Edges, Source, Destination, Target) ->\n .", "__typename": "CodeSnippetNode" }, { "lang": "Elixir", "langSlug": "elixir", "code": "defmodule Solution do\n @spec modified_graph_edges(n :: integer, edges :: [[integer]], source :: integer, destination :: integer, target :: integer) :: [[integer]]\n def modified_graph_edges(n, edges, source, destination, target) do\n\n end\nend", "__typename": "CodeSnippetNode" } ], "stats": "{\"totalAccepted\": \"3.9K\", \"totalSubmission\": \"17.4K\", \"totalAcceptedRaw\": 3910, \"totalSubmissionRaw\": 17433, \"acRate\": \"22.4%\"}", "hints": [ "Firstly, check that it’s actually possible to make the shortest path from source to destination equal to the target.", "If the shortest path from source to destination without the edges to be modified, is less than the target, then it is not possible.", "If the shortest path from source to destination including the edges to be modified and assigning them a temporary weight of 1, is greater than the target, then it is also not possible.", "Suppose we can find a modifiable edge (u, v) such that the length of the shortest path from source to u (dis1) plus the length of the shortest path from v to destination (dis2) is less than target (dis1 + dis2 < target), then we can change its weight to “target - dis1 - dis2”.", "For all the other edges that still have the weight “-1”, change the weights into sufficient large number (target, target + 1 or 200000000 etc.)." ], "solution": null, "status": null, "sampleTestCase": "5\n[[4,1,-1],[2,0,-1],[0,3,-1],[4,3,-1]]\n0\n1\n5", "metaData": "{\n \"name\": \"modifiedGraphEdges\",\n \"params\": [\n {\n \"name\": \"n\",\n \"type\": \"integer\"\n },\n {\n \"type\": \"integer[][]\",\n \"name\": \"edges\"\n },\n {\n \"type\": \"integer\",\n \"name\": \"source\"\n },\n {\n \"type\": \"integer\",\n \"name\": \"destination\"\n },\n {\n \"type\": \"integer\",\n \"name\": \"target\"\n }\n ],\n \"return\": {\n \"type\": \"integer[][]\"\n }\n}", "judgerAvailable": true, "judgeType": "large", "mysqlSchemas": [], "enableRunCode": true, "enableTestMode": false, "enableDebugger": true, "envInfo": "{\"cpp\": [\"C++\", \"

Compiled with clang 11 using the latest C++ 20 standard.

\\r\\n\\r\\n

Your code is compiled with level two optimization (-O2). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.

\\r\\n\\r\\n

Most standard library headers are already included automatically for your convenience.

\"], \"java\": [\"Java\", \"

OpenJDK 17. Java 8 features such as lambda expressions and stream API can be used.

\\r\\n\\r\\n

Most standard library headers are already included automatically for your convenience.

\\r\\n

Includes Pair class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.

\"], \"python\": [\"Python\", \"

Python 2.7.12.

\\r\\n\\r\\n

Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.

\\r\\n\\r\\n

For Map/TreeMap data structure, you may use sortedcontainers library.

\\r\\n\\r\\n

Note that Python 2.7 will not be maintained past 2020. For the latest Python, please choose Python3 instead.

\"], \"c\": [\"C\", \"

Compiled with gcc 8.2 using the gnu11 standard.

\\r\\n\\r\\n

Your code is compiled with level one optimization (-O1). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.

\\r\\n\\r\\n

Most standard library headers are already included automatically for your convenience.

\\r\\n\\r\\n

For hash table operations, you may use uthash. \\\"uthash.h\\\" is included by default. Below are some examples:

\\r\\n\\r\\n

1. Adding an item to a hash.\\r\\n

\\r\\nstruct hash_entry {\\r\\n    int id;            /* we'll use this field as the key */\\r\\n    char name[10];\\r\\n    UT_hash_handle hh; /* makes this structure hashable */\\r\\n};\\r\\n\\r\\nstruct hash_entry *users = NULL;\\r\\n\\r\\nvoid add_user(struct hash_entry *s) {\\r\\n    HASH_ADD_INT(users, id, s);\\r\\n}\\r\\n
\\r\\n

\\r\\n\\r\\n

2. Looking up an item in a hash:\\r\\n

\\r\\nstruct hash_entry *find_user(int user_id) {\\r\\n    struct hash_entry *s;\\r\\n    HASH_FIND_INT(users, &user_id, s);\\r\\n    return s;\\r\\n}\\r\\n
\\r\\n

\\r\\n\\r\\n

3. Deleting an item in a hash:\\r\\n

\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n    HASH_DEL(users, user);  \\r\\n}\\r\\n
\\r\\n

\"], \"csharp\": [\"C#\", \"

C# 10 with .NET 6 runtime

\"], \"javascript\": [\"JavaScript\", \"

Node.js 16.13.2.

\\r\\n\\r\\n

Your code is run with --harmony flag, enabling new ES6 features.

\\r\\n\\r\\n

lodash.js library is included by default.

\\r\\n\\r\\n

For Priority Queue / Queue data structures, you may use 5.3.0 version of datastructures-js/priority-queue and 4.2.1 version of datastructures-js/queue.

\"], \"ruby\": [\"Ruby\", \"

Ruby 3.1

\\r\\n\\r\\n

Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms

\"], \"swift\": [\"Swift\", \"

Swift 5.5.2.

\"], \"golang\": [\"Go\", \"

Go 1.21

\\r\\n

Support https://godoc.org/github.com/emirpasic/gods@v1.18.1 library.

\"], \"python3\": [\"Python3\", \"

Python 3.10.

\\r\\n\\r\\n

Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.

\\r\\n\\r\\n

For Map/TreeMap data structure, you may use sortedcontainers library.

\"], \"scala\": [\"Scala\", \"

Scala 2.13.7.

\"], \"kotlin\": [\"Kotlin\", \"

Kotlin 1.9.0.

\"], \"rust\": [\"Rust\", \"

Rust 1.58.1

\\r\\n\\r\\n

Supports rand v0.6\\u00a0from crates.io

\"], \"php\": [\"PHP\", \"

PHP 8.1.

\\r\\n

With bcmath module

\"], \"typescript\": [\"Typescript\", \"

TypeScript 5.1.6, Node.js 16.13.2.

\\r\\n\\r\\n

Your code is run with --harmony flag, enabling new ES2022 features.

\\r\\n\\r\\n

lodash.js library is included by default.

\"], \"racket\": [\"Racket\", \"

Run with Racket 8.3.

\"], \"erlang\": [\"Erlang\", \"Erlang/OTP 25.0\"], \"elixir\": [\"Elixir\", \"Elixir 1.13.4 with Erlang/OTP 25.0\"], \"dart\": [\"Dart\", \"

Dart 2.17.3

\\r\\n\\r\\n

Your code will be run directly without compiling

\"]}", "libraryUrl": null, "adminUrl": null, "challengeQuestion": null, "__typename": "QuestionNode" } } }