{ "data": { "question": { "questionId": "736", "questionFrontendId": "736", "boundTopicId": null, "title": "Parse Lisp Expression", "titleSlug": "parse-lisp-expression", "content": "

You are given a string expression representing a Lisp-like expression to return the integer value of.

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The syntax for these expressions is given as follows.

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Example 1:

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\nInput: expression = "(let x 2 (mult x (let x 3 y 4 (add x y))))"\nOutput: 14\nExplanation: In the expression (add x y), when checking for the value of the variable x,\nwe check from the innermost scope to the outermost in the context of the variable we are trying to evaluate.\nSince x = 3 is found first, the value of x is 3.\n
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Example 2:

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\nInput: expression = "(let x 3 x 2 x)"\nOutput: 2\nExplanation: Assignment in let statements is processed sequentially.\n
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Example 3:

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\nInput: expression = "(let x 1 y 2 x (add x y) (add x y))"\nOutput: 5\nExplanation: The first (add x y) evaluates as 3, and is assigned to x.\nThe second (add x y) evaluates as 3+2 = 5.\n
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Constraints:

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Recall it by checking the current scope in reverse order.\r\n\r\n* Otherwise, group the tokens (variables or expressions) within this expression by counting the \"balance\" `bal` of the occurrences of `'('` minus the number of occurrences of `')'`. When the balance is zero, we have ended a token. For example, `(add 1 (add 2 3))` should have tokens `'1'` and `'(add 2 3)'`.\r\n\r\n* For add and mult expressions, evaluate each token and return the addition or multiplication of them.\r\n\r\n* For let expressions, evaluate each expression sequentially and assign it to the variable in the current scope, then return the evaluation of the final expression." ], "solution": null, "status": null, "sampleTestCase": "\"(let x 2 (mult x (let x 3 y 4 (add x y))))\"", "metaData": "{\r\n \"name\": \"evaluate\",\r\n \"params\": [\r\n {\r\n \"name\": \"expression\",\r\n \"type\": \"string\"\r\n }\r\n ],\r\n \"return\": {\r\n \"type\": \"integer\"\r\n }\r\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.

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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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Python 2.7.12.

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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.

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Compiled with gcc 8.2 using the gnu99 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

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\\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
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C# 10 with .NET 6 runtime

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Your code is compiled with debug flag enabled (/debug).

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Node.js 16.13.2.

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Ruby 3.1

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Swift 5.5.2.

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Go 1.17.6.

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Python 3.10.

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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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With bcmath module

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TypeScript 4.5.4, Node.js 16.13.2.

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Run with Racket 8.3.

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