{ "data": { "question": { "questionId": "2233", "questionFrontendId": "2110", "categoryTitle": "Algorithms", "boundTopicId": 1158898, "title": "Number of Smooth Descent Periods of a Stock", "titleSlug": "number-of-smooth-descent-periods-of-a-stock", "content": "
You are given an integer array prices representing the daily price history of a stock, where prices[i] is the stock price on the ith day.
A smooth descent period of a stock consists of one or more contiguous days such that the price on each day is lower than the price on the preceding day by exactly 1. The first day of the period is exempted from this rule.
Return the number of smooth descent periods.
\n\n\n
Example 1:
\n\n\nInput: prices = [3,2,1,4]\nOutput: 7\nExplanation: There are 7 smooth descent periods:\n[3], [2], [1], [4], [3,2], [2,1], and [3,2,1]\nNote that a period with one day is a smooth descent period by the definition.\n\n\n
Example 2:
\n\n\nInput: prices = [8,6,7,7]\nOutput: 4\nExplanation: There are 4 smooth descent periods: [8], [6], [7], and [7]\nNote that [8,6] is not a smooth descent period as 8 - 6 ≠ 1.\n\n\n
Example 3:
\n\n\nInput: prices = [1]\nOutput: 1\nExplanation: There is 1 smooth descent period: [1]\n\n\n
\n
Constraints:
\n\n1 <= prices.length <= 1051 <= prices[i] <= 105给你一个整数数组 prices ,表示一支股票的历史每日股价,其中 prices[i] 是这支股票第 i 天的价格。
一个 平滑下降的阶段 定义为:对于 连续一天或者多天 ,每日股价都比 前一日股价恰好少 1 ,这个阶段第一天的股价没有限制。
请你返回 平滑下降阶段 的数目。
\n\n\n\n
示例 1:
\n\n输入:prices = [3,2,1,4]\n输出:7\n解释:总共有 7 个平滑下降阶段:\n[3], [2], [1], [4], [3,2], [2,1] 和 [3,2,1]\n注意,仅一天按照定义也是平滑下降阶段。\n\n\n
示例 2:
\n\n输入:prices = [8,6,7,7]\n输出:4\n解释:总共有 4 个连续平滑下降阶段:[8], [6], [7] 和 [7]\n由于 8 - 6 ≠ 1 ,所以 [8,6] 不是平滑下降阶段。\n\n\n
示例 3:
\n\n输入:prices = [1]\n输出:1\n解释:总共有 1 个平滑下降阶段:[1]\n\n\n
\n\n
提示:
\n\n1 <= prices.length <= 1051 <= prices[i] <= 105\\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 \\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\\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# 13<\\/a> \\u8fd0\\u884c\\u5728 .NET 9 \\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 \\u60a8\\u53ef\\u4f7f\\u7528 datastructures-js <\\/a>\\u5e93\\u6240\\u63d0\\u4f9b\\u7684\\u6570\\u636e\\u7ed3\\u6784\\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 \\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\\uff1a \\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\\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 \\u7248\\u672c\\uff1a \\u652f\\u6301 crates.io \\u7684 rand<\\/a>\\u3001regex<\\/a> \\u548c itertools<\\/a><\\/p>\"],\"php\":[\"PHP\",\" 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 \\u60a8\\u53ef\\u4f7f\\u7528 datastructures-js <\\/a>\\u5e93\\u6240\\u63d0\\u4f9b\\u7684\\u6570\\u636e\\u7ed3\\u6784\\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 \\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": "[3,2,1,4]\n[8,6,7,7]\n[1]",
"__typename": "QuestionNode"
}
}
}clang 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-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\\nOpenJDK 21<\\/code>\\u3002\\u4f7f\\u7528\\u7f16\\u8bd1\\u53c2\\u6570 --enable-preview --release 21<\\/code><\\/p>\\r\\n\\r\\nPython 2.7.18<\\/code><\\/p>\\r\\n\\r\\nGCC 14<\\/code>\\uff0c\\u91c7\\u7528 GNU11 \\u6807\\u51c6\\u3002<\\/p>\\r\\n\\r\\n-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\\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 22.14.0<\\/code><\\/p>\\r\\n\\r\\n--harmony<\\/code> \\u6807\\u8bb0\\u6765\\u5f00\\u542f \\u65b0\\u7248ES6\\u7279\\u6027<\\/a>\\u3002<\\/p>\\r\\n\\r\\nRuby 3.2<\\/code> \\u6267\\u884c<\\/p>\\r\\n\\r\\nSwift 6.0<\\/code><\\/p>\\r\\n\\r\\nGo 1.23<\\/code><\\/p>\\r\\n\\r\\nPython 3.11<\\/code><\\/p>\\r\\n\\r\\nScala 3.3.1<\\/code><\\/p>\"],\"kotlin\":[\"Kotlin\",\"Kotlin 2.1.10<\\/code><\\/p>\"],\"rust\":[\"Rust\",\"rust 1.88.0<\\/code>\\uff0c\\u4f7f\\u7528 edition 2024\\u3002<\\/p>\\r\\n\\r\\nPHP 8.2<\\/code>.<\\/p>\\r\\n\\r\\n-O2 --disable-reflection<\\/code><\\/p>\\r\\n\\r\\n