A sentence is a list of words that are separated by a single space with no leading or trailing spaces.
\n\n"Hello World", "HELLO", "hello world hello world" are all sentences.Words consist of only uppercase and lowercase English letters. Uppercase and lowercase English letters are considered different.
\n\nA sentence is circular if:
\n\nFor example, "leetcode exercises sound delightful", "eetcode", "leetcode eats soul" are all circular sentences. However, "Leetcode is cool", "happy Leetcode", "Leetcode" and "I like Leetcode" are not circular sentences.
Given a string sentence, return true if it is circular. Otherwise, return false.
\n
Example 1:
\n\n\nInput: sentence = "leetcode exercises sound delightful"\nOutput: true\nExplanation: The words in sentence are ["leetcode", "exercises", "sound", "delightful"].\n- leetcode's last character is equal to exercises's first character.\n- exercises's last character is equal to sound's first character.\n- sound's last character is equal to delightful's first character.\n- delightful's last character is equal to leetcode's first character.\nThe sentence is circular.\n\n
Example 2:
\n\n\nInput: sentence = "eetcode"\nOutput: true\nExplanation: The words in sentence are ["eetcode"].\n- eetcode's last character is equal to eetcode's first character.\nThe sentence is circular.\n\n
Example 3:
\n\n\nInput: sentence = "Leetcode is cool"\nOutput: false\nExplanation: The words in sentence are ["Leetcode", "is", "cool"].\n- Leetcode's last character is not equal to is's first character.\nThe sentence is not circular.\n\n
\n
Constraints:
\n\n1 <= sentence.length <= 500sentence consist of only lowercase and uppercase English letters and spaces.sentence are separated by a single space.句子 是由单个空格分隔的一组单词，且不含前导或尾随空格。
\n\n\"Hello World\"、\"HELLO\"、\"hello world hello world\" 都是符合要求的句子。单词 仅 由大写和小写英文字母组成。且大写和小写字母会视作不同字符。
\n\n如果句子满足下述全部条件，则认为它是一个 回环句 ：
\n\n例如，\"leetcode exercises sound delightful\"、\"eetcode\"、\"leetcode eats soul\" 都是回环句。然而，\"Leetcode is cool\"、\"happy Leetcode\"、\"Leetcode\" 和 \"I like Leetcode\" 都 不 是回环句。
给你一个字符串 sentence ，请你判断它是不是一个回环句。如果是，返回 true ；否则，返回 false 。
\n\n
示例 1：
\n\n\n输入：sentence = \"leetcode exercises sound delightful\"\n输出：true\n解释：句子中的单词是 [\"leetcode\", \"exercises\", \"sound\", \"delightful\"] 。\n- leetcode 的最后一个字符和 exercises 的第一个字符相等。\n- exercises 的最后一个字符和 sound 的第一个字符相等。\n- sound 的最后一个字符和 delightful 的第一个字符相等。\n- delightful 的最后一个字符和 leetcode 的第一个字符相等。\n这个句子是回环句。\n\n
示例 2：
\n\n\n输入：sentence = \"eetcode\"\n输出：true\n解释：句子中的单词是 [\"eetcode\"] 。\n- eetcode 的最后一个字符和 eetcode 的第一个字符相等。\n这个句子是回环句。\n\n
示例 3：
\n\n\n输入：sentence = \"Leetcode is cool\"\n输出：false\n解释：句子中的单词是 [\"Leetcode\", \"is\", \"cool\"] 。\n- Leetcode 的最后一个字符和 is 的第一个字符 不 相等。 \n这个句子 不 是回环句。\n\n
\n\n
提示：
\n\n1 <= sentence.length <= 500sentence 仅由大小写英文字母和空格组成sentence 中的单词由单个空格进行分隔\\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. 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\\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 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