{ "data": { "question": { "questionId": "2176", "questionFrontendId": "2050", "categoryTitle": "Algorithms", "boundTopicId": 1058758, "title": "Parallel Courses III", "titleSlug": "parallel-courses-iii", "content": "
You are given an integer n
, which indicates that there are n
courses labeled from 1
to n
. You are also given a 2D integer array relations
where relations[j] = [prevCoursej, nextCoursej]
denotes that course prevCoursej
has to be completed before course nextCoursej
(prerequisite relationship). Furthermore, you are given a 0-indexed integer array time
where time[i]
denotes how many months it takes to complete the (i+1)th
course.
You must find the minimum number of months needed to complete all the courses following these rules:
\n\nReturn the minimum number of months needed to complete all the courses.
\n\nNote: The test cases are generated such that it is possible to complete every course (i.e., the graph is a directed acyclic graph).
\n\n\n
Example 1:
\n\n\n\nInput: n = 3, relations = [[1,3],[2,3]], time = [3,2,5]\nOutput: 8\nExplanation: The figure above represents the given graph and the time required to complete each course. \nWe start course 1 and course 2 simultaneously at month 0.\nCourse 1 takes 3 months and course 2 takes 2 months to complete respectively.\nThus, the earliest time we can start course 3 is at month 3, and the total time required is 3 + 5 = 8 months.\n\n\n
Example 2:
\n\n\n\nInput: n = 5, relations = [[1,5],[2,5],[3,5],[3,4],[4,5]], time = [1,2,3,4,5]\nOutput: 12\nExplanation: The figure above represents the given graph and the time required to complete each course.\nYou can start courses 1, 2, and 3 at month 0.\nYou can complete them after 1, 2, and 3 months respectively.\nCourse 4 can be taken only after course 3 is completed, i.e., after 3 months. It is completed after 3 + 4 = 7 months.\nCourse 5 can be taken only after courses 1, 2, 3, and 4 have been completed, i.e., after max(1,2,3,7) = 7 months.\nThus, the minimum time needed to complete all the courses is 7 + 5 = 12 months.\n\n\n
\n
Constraints:
\n\n1 <= n <= 5 * 104
0 <= relations.length <= min(n * (n - 1) / 2, 5 * 104)
relations[j].length == 2
1 <= prevCoursej, nextCoursej <= n
prevCoursej != nextCoursej
[prevCoursej, nextCoursej]
are unique.time.length == n
1 <= time[i] <= 104
给你一个整数 n
,表示有 n
节课,课程编号从 1
到 n
。同时给你一个二维整数数组 relations
,其中 relations[j] = [prevCoursej, nextCoursej]
,表示课程 prevCoursej
必须在课程 nextCoursej
之前 完成(先修课的关系)。同时给你一个下标从 0 开始的整数数组 time
,其中 time[i]
表示完成第 (i+1)
门课程需要花费的 月份 数。
请你根据以下规则算出完成所有课程所需要的 最少 月份数:
\n\n请你返回完成所有课程所需要的 最少 月份数。
\n\n注意:测试数据保证一定可以完成所有课程(也就是先修课的关系构成一个有向无环图)。
\n\n\n\n
示例 1:
\n\n\n\n
输入:n = 3, relations = [[1,3],[2,3]], time = [3,2,5]\n输出:8\n解释:上图展示了输入数据所表示的先修关系图,以及完成每门课程需要花费的时间。\n你可以在月份 0 同时开始课程 1 和 2 。\n课程 1 花费 3 个月,课程 2 花费 2 个月。\n所以,最早开始课程 3 的时间是月份 3 ,完成所有课程所需时间为 3 + 5 = 8 个月。\n\n\n
示例 2:
\n\n\n\n
输入:n = 5, relations = [[1,5],[2,5],[3,5],[3,4],[4,5]], time = [1,2,3,4,5]\n输出:12\n解释:上图展示了输入数据所表示的先修关系图,以及完成每门课程需要花费的时间。\n你可以在月份 0 同时开始课程 1 ,2 和 3 。\n在月份 1,2 和 3 分别完成这三门课程。\n课程 4 需在课程 3 之后开始,也就是 3 个月后。课程 4 在 3 + 4 = 7 月完成。\n课程 5 需在课程 1,2,3 和 4 之后开始,也就是在 max(1,2,3,7) = 7 月开始。\n所以完成所有课程所需的最少时间为 7 + 5 = 12 个月。\n\n\n
\n\n
提示:
\n\n1 <= n <= 5 * 104
0 <= relations.length <= min(n * (n - 1) / 2, 5 * 104)
relations[j].length == 2
1 <= prevCoursej, nextCoursej <= n
prevCoursej != nextCoursej
[prevCoursej, nextCoursej]
都是 互不相同 的。time.length == n
1 <= time[i] <= 104
\\u7248\\u672c\\uff1a \\u7f16\\u8bd1\\u65f6\\uff0c\\u5c06\\u4f1a\\u91c7\\u7528 \\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\\uff1a \\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 \\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 \\u5c06\\u57282020\\u5e74\\u540e\\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\\uff1a \\u7f16\\u8bd1\\u65f6\\uff0c\\u5c06\\u4f1a\\u91c7\\u7528 \\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 2. \\u5728\\u54c8\\u5e0c\\u8868\\u4e2d\\u67e5\\u627e\\u4e00\\u4e2a\\u5bf9\\u8c61\\uff1a<\\/b>\\r\\n 3. \\u4ece\\u54c8\\u5e0c\\u8868\\u4e2d\\u5220\\u9664\\u4e00\\u4e2a\\u5bf9\\u8c61\\uff1a<\\/b>\\r\\n C# 10<\\/a> \\u8fd0\\u884c\\u5728 .NET 6 \\u4e0a<\\/p>\"],\"javascript\":[\"JavaScript\",\" \\u7248\\u672c\\uff1a \\u60a8\\u7684\\u4ee3\\u7801\\u5728\\u6267\\u884c\\u65f6\\u5c06\\u5e26\\u4e0a 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@5.3.0<\\/a> \\u548c datastructures-js\\/queue@4.2.1<\\/a>\\u3002<\\/p>\"],\"ruby\":[\"Ruby\",\" \\u4f7f\\u7528 \\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\\uff1a \\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\\uff1a \\u652f\\u6301 https:\\/\\/godoc.org\\/github.com\\/emirpasic\\/gods@v1.18.1<\\/a> \\u7b2c\\u4e09\\u65b9\\u5e93\\u3002<\\/p>\"],\"python3\":[\"Python3\",\" \\u7248\\u672c\\uff1a \\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\\uff1a \\u7248\\u672c\\uff1a \\u6211\\u4eec\\u4f7f\\u7528\\u7684\\u662f JetBrains \\u63d0\\u4f9b\\u7684 experimental compiler\\u3002\\u5982\\u679c\\u60a8\\u8ba4\\u4e3a\\u60a8\\u9047\\u5230\\u4e86\\u7f16\\u8bd1\\u5668\\u76f8\\u5173\\u7684\\u95ee\\u9898\\uff0c\\u8bf7\\u5411\\u6211\\u4eec\\u53cd\\u9988<\\/p>\"],\"rust\":[\"Rust\",\" \\u7248\\u672c\\uff1a \\u652f\\u6301 crates.io \\u7684 rand<\\/a><\\/p>\"],\"php\":[\"PHP\",\" With bcmath module.<\\/p>\"],\"typescript\":[\"TypeScript\",\" TypeScript 5.1.6<\\/p>\\r\\n\\r\\n Compile Options: --alwaysStrict --strictBindCallApply --strictFunctionTypes --target ES2022<\\/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@5.3.0<\\/a> \\u548c datastructures-js\\/queue@4.2.1<\\/a>\\u3002<\\/p>\"],\"racket\":[\"Racket\",\"clang 11<\\/code> \\u91c7\\u7528\\u6700\\u65b0C++ 20\\u6807\\u51c6\\u3002<\\/p>\\r\\n\\r\\n
-O2<\\/code>\\u7ea7\\u4f18\\u5316\\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
OpenJDK 17<\\/code>\\u3002\\u53ef\\u4ee5\\u4f7f\\u7528Java 8\\u7684\\u7279\\u6027\\u4f8b\\u5982\\uff0clambda expressions \\u548c stream API\\u3002<\\/p>\\r\\n\\r\\n
Python 2.7.12<\\/code><\\/p>\\r\\n\\r\\n
GCC 8.2<\\/code>\\uff0c\\u91c7\\u7528GNU11\\u6807\\u51c6\\u3002<\\/p>\\r\\n\\r\\n
-O1<\\/code>\\u7ea7\\u4f18\\u5316\\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
\\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
\\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
\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n HASH_DEL(users, user); \\r\\n}\\r\\n<\\/pre>\\r\\n<\\/p>\"],\"csharp\":[\"C#\",\"
Node.js 16.13.2<\\/code><\\/p>\\r\\n\\r\\n
--harmony<\\/code> \\u6807\\u8bb0\\u6765\\u5f00\\u542f \\u65b0\\u7248ES6\\u7279\\u6027<\\/a>\\u3002<\\/p>\\r\\n\\r\\n
Ruby 3.1<\\/code>\\u6267\\u884c<\\/p>\\r\\n\\r\\n
Swift 5.5.2<\\/code><\\/p>\\r\\n\\r\\n
Go 1.21<\\/code><\\/p>\\r\\n\\r\\n
Python 3.10<\\/code><\\/p>\\r\\n\\r\\n
Scala 2.13<\\/code><\\/p>\"],\"kotlin\":[\"Kotlin\",\"
Kotlin 1.9.0<\\/code><\\/p>\\r\\n\\r\\n
rust 1.58.1<\\/code><\\/p>\\r\\n\\r\\n
PHP 8.1<\\/code>.<\\/p>\\r\\n\\r\\n