{ "data": { "question": { "questionId": "3945", "questionFrontendId": "3648", "categoryTitle": "Algorithms", "boundTopicId": 3754153, "title": "Minimum Sensors to Cover Grid", "titleSlug": "minimum-sensors-to-cover-grid", "content": "

You are given n × m grid and an integer k.

\n\n

A sensor placed on cell (r, c) covers all cells whose Chebyshev distance from (r, c) is at most k.

\n\n

The Chebyshev distance between two cells (r1, c1) and (r2, c2) is max(|r1 − r2|,|c1 − c2|).

\n\n

Your task is to return the minimum number of sensors required to cover every cell of the grid.

\n\n

 

\n

Example 1:

\n\n
\n

Input: n = 5, m = 5, k = 1

\n\n

Output: 4

\n\n

Explanation:

\n\n

Placing sensors at positions (0, 3), (1, 0), (3, 3), and (4, 1) ensures every cell in the grid is covered. Thus, the answer is 4.

\n
\n\n

Example 2:

\n\n
\n

Input: n = 2, m = 2, k = 2

\n\n

Output: 1

\n\n

Explanation:

\n\n

With k = 2, a single sensor can cover the entire 2 * 2 grid regardless of its position. Thus, the answer is 1.

\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "覆盖网格的最少传感器数目", "translatedContent": "

给你一个 n × m 的网格和一个整数 k

\n\n

一个放置在单元格 (r, c) 的传感器可以覆盖所有与 (r, c) 的 切比雪夫距离不超过 k 的单元格。

\n\n

两个单元格 (r1, c1)(r2, c2) 之间的 切比雪夫距离 max(|r1 − r2|,|c1 − c2|)

\n\n

你的任务是返回覆盖整个网格所需传感器的 最少 数量。

\n\n

 

\n\n

示例 1:

\n\n
\n

输入: n = 5, m = 5, k = 1

\n\n

输出: 4

\n\n

解释:

\n\n

在位置 (0, 3)(1, 0)(3, 3)(4, 1) 放置传感器可以确保网格中的每个单元格都被覆盖。因此,答案是 4。

\n
\n\n

示例 2:

\n\n
\n

输入: n = 2, m = 2, k = 2

\n\n

输出: 1

\n\n

解释:

\n\n

k = 2 时,无论传感器放在哪个位置,单个传感器都可以覆盖整个 2 * 2 的网格。因此,答案是 1。

\n
\n\n

 

\n\n

提示:

\n\n\n", "isPaidOnly": false, "difficulty": "Medium", "likes": 8, "dislikes": 0, "isLiked": null, "similarQuestions": "[]", "contributors": [], "langToValidPlayground": "{\"cpp\": true, \"java\": true, \"python\": true, \"python3\": true, \"mysql\": false, \"mssql\": false, \"oraclesql\": false, \"c\": false, \"csharp\": false, \"javascript\": false, \"typescript\": false, \"bash\": false, \"php\": false, \"swift\": false, \"kotlin\": false, \"dart\": false, \"golang\": false, \"ruby\": false, \"scala\": false, \"html\": false, \"pythonml\": false, \"rust\": false, \"racket\": false, \"erlang\": false, \"elixir\": false, \"pythondata\": false, \"react\": false, \"vanillajs\": false, \"postgresql\": false, \"cangjie\": false}", "topicTags": [], "companyTagStats": null, "codeSnippets": [ { "lang": "C++", "langSlug": "cpp", "code": "class Solution {\npublic:\n int minSensors(int n, int m, int k) {\n \n }\n};", "__typename": "CodeSnippetNode" }, { "lang": "Java", "langSlug": "java", "code": "class Solution {\n public int minSensors(int n, int m, int k) {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Python", "langSlug": "python", "code": "class Solution(object):\n def minSensors(self, n, m, k):\n \"\"\"\n :type n: int\n :type m: int\n :type k: int\n :rtype: int\n \"\"\"\n ", "__typename": "CodeSnippetNode" }, { "lang": "Python3", "langSlug": "python3", "code": "class Solution:\n def minSensors(self, n: int, m: int, k: int) -> int:\n ", "__typename": "CodeSnippetNode" }, { "lang": "C", "langSlug": "c", "code": "int minSensors(int n, int m, int k) {\n \n}", "__typename": "CodeSnippetNode" }, { "lang": "C#", "langSlug": "csharp", "code": "public class Solution {\n public int MinSensors(int n, int m, int k) {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "JavaScript", "langSlug": "javascript", "code": "/**\n * @param {number} n\n * @param {number} m\n * @param {number} k\n * @return {number}\n */\nvar minSensors = function(n, m, k) {\n \n};", "__typename": "CodeSnippetNode" }, { "lang": "TypeScript", "langSlug": "typescript", "code": "function minSensors(n: number, m: number, k: number): number {\n \n};", "__typename": "CodeSnippetNode" }, { "lang": "PHP", "langSlug": "php", "code": "class Solution {\n\n /**\n * @param Integer $n\n * @param Integer $m\n * @param Integer $k\n * @return Integer\n */\n function minSensors($n, $m, $k) {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Swift", "langSlug": "swift", "code": "class Solution {\n func minSensors(_ n: Int, _ m: Int, _ k: Int) -> Int {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Kotlin", "langSlug": "kotlin", "code": "class Solution {\n fun minSensors(n: Int, m: Int, k: Int): Int {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Dart", "langSlug": "dart", "code": "class Solution {\n int minSensors(int n, int m, int k) {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Go", "langSlug": "golang", "code": "func minSensors(n int, m int, k int) int {\n \n}", "__typename": "CodeSnippetNode" }, { "lang": "Ruby", "langSlug": "ruby", "code": "# @param {Integer} n\n# @param {Integer} m\n# @param {Integer} k\n# @return {Integer}\ndef min_sensors(n, m, k)\n \nend", "__typename": "CodeSnippetNode" }, { "lang": "Scala", "langSlug": "scala", "code": "object Solution {\n def minSensors(n: Int, m: Int, k: Int): Int = {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Rust", "langSlug": "rust", "code": "impl Solution {\n pub fn min_sensors(n: i32, m: i32, k: i32) -> i32 {\n \n }\n}", "__typename": "CodeSnippetNode" }, { "lang": "Racket", "langSlug": "racket", "code": "(define/contract (min-sensors n m k)\n (-> exact-integer? exact-integer? exact-integer? exact-integer?)\n )", "__typename": "CodeSnippetNode" }, { "lang": "Erlang", "langSlug": "erlang", "code": "-spec min_sensors(N :: integer(), M :: integer(), K :: integer()) -> integer().\nmin_sensors(N, M, K) ->\n .", "__typename": "CodeSnippetNode" }, { "lang": "Elixir", "langSlug": "elixir", "code": "defmodule Solution do\n @spec min_sensors(n :: integer, m :: integer, k :: integer) :: integer\n def min_sensors(n, m, k) do\n \n end\nend", "__typename": "CodeSnippetNode" }, { "lang": "Cangjie", "langSlug": "cangjie", "code": "class Solution {\n func minSensors(n: Int64, m: Int64, k: Int64): Int64 {\n\n }\n}", "__typename": "CodeSnippetNode" } ], "stats": "{\"totalAccepted\": \"1.7K\", \"totalSubmission\": \"2.5K\", \"totalAcceptedRaw\": 1674, \"totalSubmissionRaw\": 2457, \"acRate\": \"68.1%\"}", "hints": [ "Let s = 2*k + 1, the side length each sensor covers.", "The minimum number is ceil(n / s) * ceil(m / s)." ], "solution": null, "status": null, "sampleTestCase": "5\n5\n1", "metaData": "{\n \"name\": \"minSensors\",\n \"params\": [\n {\n \"name\": \"n\",\n \"type\": \"integer\"\n },\n {\n \"type\": \"integer\",\n \"name\": \"m\"\n },\n {\n \"type\": \"integer\",\n \"name\": \"k\"\n }\n ],\n \"return\": {\n \"type\": \"integer\"\n }\n}", "judgerAvailable": true, "judgeType": "large", "mysqlSchemas": [], "enableRunCode": true, "envInfo": "{\"cpp\":[\"C++\",\"

\\u7248\\u672c\\uff1aclang 19<\\/code> \\u91c7\\u7528\\u6700\\u65b0 C++ 23 \\u6807\\u51c6\\uff0c\\u5e76\\u4f7f\\u7528 GCC 14 \\u63d0\\u4f9b\\u7684 libstdc++<\\/code>\\u3002<\\/p>\\r\\n\\r\\n

\\u7f16\\u8bd1\\u65f6\\uff0c\\u5c06\\u4f1a\\u91c7\\u7528 -O2<\\/code> \\u7ea7\\u4f18\\u5316\\uff0c\\u5e76\\u63d0\\u4f9b -gline-tables-only<\\/code> \\u53c2\\u6570\\u3002AddressSanitizer<\\/a> \\u4e5f\\u88ab\\u5f00\\u542f\\u6765\\u68c0\\u6d4b out-of-bounds<\\/code> \\u548c use-after-free<\\/code> \\u9519\\u8bef\\u3002<\\/p>\\r\\n\\r\\n

\\u4e3a\\u4e86\\u4f7f\\u7528\\u65b9\\u4fbf\\uff0c\\u5927\\u90e8\\u5206\\u6807\\u51c6\\u5e93\\u7684\\u5934\\u6587\\u4ef6\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8\\u5bfc\\u5165\\u3002<\\/p>\"],\"java\":[\"Java\",\"

\\u7248\\u672c\\uff1aOpenJDK 21<\\/code>\\u3002\\u4f7f\\u7528\\u7f16\\u8bd1\\u53c2\\u6570 --enable-preview --release 21<\\/code><\\/p>\\r\\n\\r\\n

\\u4e3a\\u4e86\\u65b9\\u4fbf\\u8d77\\u89c1\\uff0c\\u5927\\u90e8\\u5206\\u6807\\u51c6\\u5e93\\u7684\\u5934\\u6587\\u4ef6\\u5df2\\u88ab\\u5bfc\\u5165\\u3002<\\/p>\\r\\n\\r\\n

\\u5305\\u542b Pair \\u7c7b: https:\\/\\/docs.oracle.com\\/javase\\/8\\/javafx\\/api\\/javafx\\/util\\/Pair.html <\\/p>\"],\"python\":[\"Python\",\"

\\u7248\\u672c\\uff1a Python 2.7.18<\\/code><\\/p>\\r\\n\\r\\n

\\u4e3a\\u4e86\\u65b9\\u4fbf\\u8d77\\u89c1\\uff0c\\u5927\\u90e8\\u5206\\u5e38\\u7528\\u5e93\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8 \\u5bfc\\u5165\\uff0c\\u5982\\uff1aarray<\\/a>, bisect<\\/a>, collections<\\/a>\\u3002\\u5982\\u679c\\u60a8\\u9700\\u8981\\u4f7f\\u7528\\u5176\\u4ed6\\u5e93\\u51fd\\u6570\\uff0c\\u8bf7\\u81ea\\u884c\\u5bfc\\u5165\\u3002<\\/p>\\r\\n\\r\\n

\\u6ce8\\u610f Python 2.7 \\u5df2\\u4e0d\\u518d\\u7ef4\\u62a4<\\/a>\\u3002 \\u5982\\u60f3\\u4f7f\\u7528\\u6700\\u65b0\\u7248\\u7684Python\\uff0c\\u8bf7\\u9009\\u62e9Python 3\\u3002<\\/p>\"],\"c\":[\"C\",\"

\\u7248\\u672c\\uff1aGCC 14<\\/code>\\uff0c\\u91c7\\u7528 GNU11 \\u6807\\u51c6\\u3002<\\/p>\\r\\n\\r\\n

\\u7f16\\u8bd1\\u65f6\\uff0c\\u5c06\\u4f1a\\u91c7\\u7528 -O2<\\/code> \\u7ea7\\u4f18\\u5316\\uff0c\\u5e76\\u63d0\\u4f9b -g1<\\/code> \\u53c2\\u6570\\u3002 AddressSanitizer<\\/a> \\u4e5f\\u88ab\\u5f00\\u542f\\u6765\\u68c0\\u6d4b out-of-bounds<\\/code> \\u548c use-after-free<\\/code> \\u9519\\u8bef\\u3002<\\/p>\\r\\n\\r\\n

\\u4e3a\\u4e86\\u4f7f\\u7528\\u65b9\\u4fbf\\uff0c\\u5927\\u90e8\\u5206\\u6807\\u51c6\\u5e93\\u7684\\u5934\\u6587\\u4ef6\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8\\u5bfc\\u5165\\u3002<\\/p>\\r\\n\\r\\n

\\u5982\\u60f3\\u4f7f\\u7528\\u54c8\\u5e0c\\u8868\\u8fd0\\u7b97, \\u60a8\\u53ef\\u4ee5\\u4f7f\\u7528 uthash<\\/a>\\u3002 \\\"uthash.h\\\"\\u5df2\\u7ecf\\u9ed8\\u8ba4\\u88ab\\u5bfc\\u5165\\u3002\\u8bf7\\u770b\\u5982\\u4e0b\\u793a\\u4f8b:<\\/p>\\r\\n\\r\\n

1. \\u5f80\\u54c8\\u5e0c\\u8868\\u4e2d\\u6dfb\\u52a0\\u4e00\\u4e2a\\u5bf9\\u8c61\\uff1a<\\/b>\\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<\\/pre>\\r\\n<\\/p>\\r\\n\\r\\n

2. \\u5728\\u54c8\\u5e0c\\u8868\\u4e2d\\u67e5\\u627e\\u4e00\\u4e2a\\u5bf9\\u8c61\\uff1a<\\/b>\\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<\\/pre>\\r\\n<\\/p>\\r\\n\\r\\n

3. \\u4ece\\u54c8\\u5e0c\\u8868\\u4e2d\\u5220\\u9664\\u4e00\\u4e2a\\u5bf9\\u8c61\\uff1a<\\/b>\\r\\n

\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n    HASH_DEL(users, user);  \\r\\n}\\r\\n<\\/pre>\\r\\n<\\/p>\"],\"csharp\":[\"C#\",\"

C# 13<\\/a> \\u8fd0\\u884c\\u5728 .NET 9 \\u4e0a<\\/p>\"],\"javascript\":[\"JavaScript\",\"

\\u7248\\u672c\\uff1aNode.js 22.14.0<\\/code><\\/p>\\r\\n\\r\\n

\\u60a8\\u7684\\u4ee3\\u7801\\u5728\\u6267\\u884c\\u65f6\\u5c06\\u5e26\\u4e0a --harmony<\\/code> \\u6807\\u8bb0\\u6765\\u5f00\\u542f \\u65b0\\u7248ES6\\u7279\\u6027<\\/a>\\u3002<\\/p>\\r\\n\\r\\n

lodash.js<\\/a> \\u5e93\\u5df2\\u7ecf\\u9ed8\\u8ba4\\u88ab\\u5305\\u542b\\u3002<\\/p>\\r\\n\\r\\n

\\u5982\\u9700\\u4f7f\\u7528\\u961f\\u5217\\/\\u4f18\\u5148\\u961f\\u5217\\uff0c\\u60a8\\u53ef\\u4f7f\\u7528 datastructures-js\\/priority-queue@6.3.2<\\/a>\\uff0c datastructures-js\\/queue@4.2.3<\\/a> \\u4ee5\\u53ca datastructures-js\\/deque@1.0.4<\\/a>\\u3002<\\/p>\"],\"ruby\":[\"Ruby\",\"

\\u4f7f\\u7528 Ruby 3.2<\\/code> \\u6267\\u884c<\\/p>\\r\\n\\r\\n

\\u4e00\\u4e9b\\u5e38\\u7528\\u7684\\u6570\\u636e\\u7ed3\\u6784\\u5df2\\u5728 Algorithms \\u6a21\\u5757\\u4e2d\\u63d0\\u4f9b\\uff1ahttps:\\/\\/www.rubydoc.info\\/github\\/kanwei\\/algorithms\\/Algorithms<\\/p>\"],\"swift\":[\"Swift\",\"

\\u7248\\u672c\\uff1aSwift 6.0<\\/code><\\/p>\\r\\n\\r\\n

\\u60a8\\u53ef\\u4ee5\\u4f7f\\u7528 swift-algorithms 1.2.0<\\/a>\\uff0cswift-collections 1.1.4<\\/a> \\u548c swift-numerics 1.0.2<\\/a><\\/p>\\r\\n\\r\\n

\\u6211\\u4eec\\u901a\\u5e38\\u4fdd\\u8bc1\\u66f4\\u65b0\\u5230 Apple\\u653e\\u51fa\\u7684\\u6700\\u65b0\\u7248Swift<\\/a>\\u3002\\u5982\\u679c\\u60a8\\u53d1\\u73b0Swift\\u4e0d\\u662f\\u6700\\u65b0\\u7248\\u7684\\uff0c\\u8bf7\\u8054\\u7cfb\\u6211\\u4eec\\uff01\\u6211\\u4eec\\u5c06\\u5c3d\\u5feb\\u66f4\\u65b0\\u3002<\\/p>\"],\"golang\":[\"Go\",\"

\\u7248\\u672c\\uff1aGo 1.23<\\/code><\\/p>\\r\\n\\r\\n

\\u652f\\u6301 https:\\/\\/pkg.go.dev\\/github.com\\/emirpasic\\/gods@v1.18.1<\\/a> \\u548c https:\\/\\/pkg.go.dev\\/github.com\\/emirpasic\\/gods\\/v2@v2.0.0-alpha<\\/a> \\u7b2c\\u4e09\\u65b9\\u5e93\\u3002<\\/p>\"],\"python3\":[\"Python3\",\"

\\u7248\\u672c\\uff1aPython 3.11<\\/code><\\/p>\\r\\n\\r\\n

\\u4e3a\\u4e86\\u65b9\\u4fbf\\u8d77\\u89c1\\uff0c\\u5927\\u90e8\\u5206\\u5e38\\u7528\\u5e93\\u5df2\\u7ecf\\u88ab\\u81ea\\u52a8 \\u5bfc\\u5165\\uff0c\\u5982array<\\/a>, bisect<\\/a>, collections<\\/a>\\u3002 \\u5982\\u679c\\u60a8\\u9700\\u8981\\u4f7f\\u7528\\u5176\\u4ed6\\u5e93\\u51fd\\u6570\\uff0c\\u8bf7\\u81ea\\u884c\\u5bfc\\u5165\\u3002<\\/p>\\r\\n\\r\\n

\\u5982\\u9700\\u4f7f\\u7528 Map\\/TreeMap \\u6570\\u636e\\u7ed3\\u6784\\uff0c\\u60a8\\u53ef\\u4f7f\\u7528 sortedcontainers<\\/a> \\u5e93\\u3002<\\/p>\"],\"scala\":[\"Scala\",\"

\\u7248\\u672c\\uff1aScala 3.3.1<\\/code><\\/p>\"],\"kotlin\":[\"Kotlin\",\"

\\u7248\\u672c\\uff1aKotlin 2.1.10<\\/code><\\/p>\"],\"rust\":[\"Rust\",\"

\\u7248\\u672c\\uff1arust 1.88.0<\\/code>\\uff0c\\u4f7f\\u7528 edition 2024\\u3002<\\/p>\\r\\n\\r\\n

\\u652f\\u6301 crates.io \\u7684 rand<\\/a>\\u3001regex<\\/a> \\u548c itertools<\\/a><\\/p>\"],\"php\":[\"PHP\",\"

PHP 8.2<\\/code>.<\\/p>\\r\\n\\r\\n

With bcmath module.<\\/p>\"],\"typescript\":[\"TypeScript\",\"

TypeScript 5.7.3<\\/p>\\r\\n\\r\\n

Compile Options: --alwaysStrict --strictBindCallApply --strictFunctionTypes --target ES2024<\\/p>\\r\\n\\r\\n

lodash.js<\\/a> \\u5e93\\u5df2\\u7ecf\\u9ed8\\u8ba4\\u88ab\\u5305\\u542b\\u3002<\\/p>\\r\\n\\r\\n

\\u5982\\u9700\\u4f7f\\u7528\\u961f\\u5217\\/\\u4f18\\u5148\\u961f\\u5217\\uff0c\\u60a8\\u53ef\\u4f7f\\u7528 datastructures-js\\/priority-queue@6.3.2<\\/a>\\uff0c datastructures-js\\/queue@4.2.3<\\/a> \\u4ee5\\u53ca datastructures-js\\/deque@1.0.4<\\/a>\\u3002<\\/p>\"],\"racket\":[\"Racket\",\"

Racket CS<\\/a> v8.15<\\/p>\\r\\n\\r\\n

\\u4f7f\\u7528 #lang racket<\\/p>\\r\\n\\r\\n

\\u5df2\\u9884\\u5148 (require data\\/gvector data\\/queue data\\/order data\\/heap). \\u82e5\\u9700\\u4f7f\\u7528\\u5176\\u5b83\\u6570\\u636e\\u7ed3\\u6784\\uff0c\\u53ef\\u81ea\\u884c require\\u3002<\\/p>\"],\"erlang\":[\"Erlang\",\"Erlang\\/OTP 26\"],\"elixir\":[\"Elixir\",\"Elixir 1.17 with Erlang\\/OTP 26\"],\"dart\":[\"Dart\",\"

Dart 3.2\\u3002\\u60a8\\u53ef\\u4ee5\\u4f7f\\u7528 collection<\\/a> \\u5305<\\/p>\\r\\n\\r\\n

\\u60a8\\u7684\\u4ee3\\u7801\\u5c06\\u4f1a\\u88ab\\u4e0d\\u7f16\\u8bd1\\u76f4\\u63a5\\u8fd0\\u884c<\\/p>\"],\"cangjie\":[\"Cangjie\",\"

\\u7248\\u672c\\uff1a1.0.0 LTS (cjnative)<\\/p>\\r\\n\\r\\n

\\u7f16\\u8bd1\\u53c2\\u6570\\uff1a-O2 --disable-reflection<\\/code><\\/p>\\r\\n\\r\\n

\\u5feb\\u901f\\u5165\\u95e8\\u8bf7\\u67e5\\u9605\\u300c\\u4ed3\\u9889\\u7f16\\u7a0b\\u8bed\\u8a00\\u5f00\\u53d1\\u6307\\u5357\\u300d<\\/a><\\/p>\"]}", "book": null, "isSubscribed": false, "isDailyQuestion": false, "dailyRecordStatus": null, "editorType": "CKEDITOR", "ugcQuestionId": null, "style": "LEETCODE", "exampleTestcases": "5\n5\n1\n2\n2\n2", "__typename": "QuestionNode" } } }