Sync LeetCode submission Runtime - 3 ms (14.87%), Memory - 16.6 MB (18.77%)

Author: jimit105

2580-circular-sentence/README.md

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+<p>A <strong>sentence</strong> is a list of words that are separated by a<strong> single</strong> space with no leading or trailing spaces.</p>
+
+<ul>
+	<li>For example, <code>&quot;Hello World&quot;</code>, <code>&quot;HELLO&quot;</code>, <code>&quot;hello world hello world&quot;</code> are all sentences.</li>
+</ul>
+
+<p>Words consist of <strong>only</strong> uppercase and lowercase English letters. Uppercase and lowercase English letters are considered different.</p>
+
+<p>A sentence is <strong>circular </strong>if:</p>
+
+<ul>
+	<li>The last character of a word is equal to the first character of the next word.</li>
+	<li>The last character of the last word is equal to the first character of the first word.</li>
+</ul>
+
+<p>For example, <code>&quot;leetcode exercises sound delightful&quot;</code>, <code>&quot;eetcode&quot;</code>, <code>&quot;leetcode eats soul&quot; </code>are all circular sentences. However, <code>&quot;Leetcode is cool&quot;</code>, <code>&quot;happy Leetcode&quot;</code>, <code>&quot;Leetcode&quot;</code> and <code>&quot;I like Leetcode&quot;</code> are <strong>not</strong> circular sentences.</p>
+
+<p>Given a string <code>sentence</code>, return <code>true</code><em> if it is circular</em>. Otherwise, return <code>false</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> sentence = &quot;leetcode exercises sound delightful&quot;
+<strong>Output:</strong> true
+<strong>Explanation:</strong> The words in sentence are [&quot;leetcode&quot;, &quot;exercises&quot;, &quot;sound&quot;, &quot;delightful&quot;].
+- leetcod<u>e</u>&#39;s&nbsp;last character is equal to <u>e</u>xercises&#39;s first character.
+- exercise<u>s</u>&#39;s&nbsp;last character is equal to <u>s</u>ound&#39;s first character.
+- soun<u>d</u>&#39;s&nbsp;last character is equal to <u>d</u>elightful&#39;s first character.
+- delightfu<u>l</u>&#39;s&nbsp;last character is equal to <u>l</u>eetcode&#39;s first character.
+The sentence is circular.</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> sentence = &quot;eetcode&quot;
+<strong>Output:</strong> true
+<strong>Explanation:</strong> The words in sentence are [&quot;eetcode&quot;].
+- eetcod<u>e</u>&#39;s&nbsp;last character is equal to <u>e</u>etcode&#39;s first character.
+The sentence is circular.</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> sentence = &quot;Leetcode is cool&quot;
+<strong>Output:</strong> false
+<strong>Explanation:</strong> The words in sentence are [&quot;Leetcode&quot;, &quot;is&quot;, &quot;cool&quot;].
+- Leetcod<u>e</u>&#39;s&nbsp;last character is <strong>not</strong> equal to <u>i</u>s&#39;s first character.
+The sentence is <strong>not</strong> circular.</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= sentence.length &lt;= 500</code></li>
+	<li><code>sentence</code> consist of only lowercase and uppercase English letters and spaces.</li>
+	<li>The words in <code>sentence</code> are separated by a single space.</li>
+	<li>There are no leading or trailing spaces.</li>
+</ul>

2580-circular-sentence/solution.py

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+# Approach 2: Space-optimized
+
+# Time: O(n)
+# Space: O(1)
+
+class Solution:
+    def isCircularSentence(self, sentence: str) -> bool:
+        for i in range(len(sentence)):
+            if sentence[i] == ' ' and sentence[i-1] != sentence[i+1]:
+                return False
+        return sentence[0] == sentence[-1]
+