{ "data": { "question": { "questionId": "2490", "questionFrontendId": "2355", "boundTopicId": null, "title": "Maximum Number of Books You Can Take", "titleSlug": "maximum-number-of-books-you-can-take", "content": null, "translatedTitle": null, "translatedContent": null, "isPaidOnly": true, "difficulty": "Hard", "likes": 7, "dislikes": 0, "isLiked": null, "similarQuestions": "[{\"title\": \"Longest Increasing Subsequence\", \"titleSlug\": \"longest-increasing-subsequence\", \"difficulty\": \"Medium\", \"translatedTitle\": null}, {\"title\": \"Maximum Ascending Subarray Sum\", \"titleSlug\": \"maximum-ascending-subarray-sum\", \"difficulty\": \"Easy\", \"translatedTitle\": null}]", "exampleTestcases": "[8,5,2,7,9]\n[7,0,3,4,5]\n[8,2,3,7,3,4,0,1,4,3]", "categoryTitle": "Algorithms", "contributors": [], "topicTags": [], "companyTagStats": null, "codeSnippets": null, "stats": "{\"totalAccepted\": \"133\", \"totalSubmission\": \"254\", \"totalAcceptedRaw\": 133, \"totalSubmissionRaw\": 254, \"acRate\": \"52.4%\"}", "hints": [ "Create a dp array where dp[i] is the maximum number of books you can take if you can only take books from bookshelves 0 to i and you must take books from bookshelf i.", "Keep taking as many books as you can (i.e. starting from bookshelf i and going backwards, you take arr[i], arr[i] - 1, arr[i] - 2, … books).", "You may reach an index j where arr[j] < arr[i] - (i - j). Have we already found the maximum number of books you can take from bookshelves 0 to j? How do we quickly find such an index j?", "Keep a stack of possible indices for j. If x is the number at the top of the stack, keep popping from the stack while arr[x] ≥ arr[i] - (i - x). This is because if the inequality mentioned before is true, x will never be an index j as index i will run out of items first." ], "solution": null, "status": null, "sampleTestCase": "[8,5,2,7,9]", "metaData": "{\n \"name\": \"maximumBooks\",\n \"params\": [\n {\n \"name\": \"books\",\n \"type\": \"integer[]\"\n }\n ],\n \"return\": {\n \"type\": \"long\"\n }\n}", "judgerAvailable": true, "judgeType": "large", "mysqlSchemas": [], "enableRunCode": true, "enableTestMode": false, "enableDebugger": true, "envInfo": "{\"cpp\": [\"C++\", \"

Compiled with clang 11 using the latest C++ 17 standard.

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

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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.

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

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

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Python 2.7.12.

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

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

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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.

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

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

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

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

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

C# 10 with .NET 6 runtime

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Node.js 16.13.2.

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

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lodash.js library is included by default.

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

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Ruby 3.1

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

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Swift 5.5.2.

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Go 1.17.6.

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

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Python 3.10.

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

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

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Scala 2.13.7.

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Kotlin 1.3.10.

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Rust 1.58.1

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Supports rand v0.6\\u00a0from crates.io

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PHP 8.1.

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With bcmath module

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TypeScript 4.5.4, Node.js 16.13.2.

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Your code is run with --harmony flag, enabling new ES2020 features.

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lodash.js library is included by default.

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

Run with Racket 8.3.

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Dart 2.17.3

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Your code will be run directly without compiling

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