Sync LeetCode submission Runtime - 739 ms (40.53%), Memory - 22.7 MB (11.63%)

Author: jimit105

3483-alternating-groups-ii/README.md

@@ -0,0 +1,66 @@
+<p>There is a circle of red and blue tiles. You are given an array of integers <code>colors</code> and an integer <code>k</code>. The color of tile <code>i</code> is represented by <code>colors[i]</code>:</p>
+
+<ul>
+	<li><code>colors[i] == 0</code> means that tile <code>i</code> is <strong>red</strong>.</li>
+	<li><code>colors[i] == 1</code> means that tile <code>i</code> is <strong>blue</strong>.</li>
+</ul>
+
+<p>An <strong>alternating</strong> group is every <code>k</code> contiguous tiles in the circle with <strong>alternating</strong> colors (each tile in the group except the first and last one has a different color from its <strong>left</strong> and <strong>right</strong> tiles).</p>
+
+<p>Return the number of <strong>alternating</strong> groups.</p>
+
+<p><strong>Note</strong> that since <code>colors</code> represents a <strong>circle</strong>, the <strong>first</strong> and the <strong>last</strong> tiles are considered to be next to each other.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<div class="example-block">
+<p><strong>Input:</strong> <span class="example-io">colors = [0,1,0,1,0], k = 3</span></p>
+
+<p><strong>Output:</strong> <span class="example-io">3</span></p>
+
+<p><strong>Explanation:</strong></p>
+
+<p><strong><img alt="" data-darkreader-inline-bgcolor="" data-darkreader-inline-bgimage="" src="https://assets.leetcode.com/uploads/2024/06/19/screenshot-2024-05-28-183519.png" style="width: 150px; height: 150px; padding: 10px; background: rgb(255, 255, 255); border-radius: 0.5rem; --darkreader-inline-bgimage: initial; --darkreader-inline-bgcolor: #181a1b;" /></strong></p>
+
+<p>Alternating groups:</p>
+
+<p><img alt="" data-darkreader-inline-bgcolor="" data-darkreader-inline-bgimage="" src="https://assets.leetcode.com/uploads/2024/05/28/screenshot-2024-05-28-182448.png" style="width: 150px; height: 150px; padding: 10px; background: rgb(255, 255, 255); border-radius: 0.5rem; --darkreader-inline-bgimage: initial; --darkreader-inline-bgcolor: #181a1b;" /><img alt="" data-darkreader-inline-bgcolor="" data-darkreader-inline-bgimage="" src="https://assets.leetcode.com/uploads/2024/05/28/screenshot-2024-05-28-182844.png" style="width: 150px; height: 150px; padding: 10px; background: rgb(255, 255, 255); border-radius: 0.5rem; --darkreader-inline-bgimage: initial; --darkreader-inline-bgcolor: #181a1b;" /><img alt="" data-darkreader-inline-bgcolor="" data-darkreader-inline-bgimage="" src="https://assets.leetcode.com/uploads/2024/05/28/screenshot-2024-05-28-183057.png" style="width: 150px; height: 150px; padding: 10px; background: rgb(255, 255, 255); border-radius: 0.5rem; --darkreader-inline-bgimage: initial; --darkreader-inline-bgcolor: #181a1b;" /></p>
+</div>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<div class="example-block">
+<p><strong>Input:</strong> <span class="example-io">colors = [0,1,0,0,1,0,1], k = 6</span></p>
+
+<p><strong>Output:</strong> <span class="example-io">2</span></p>
+
+<p><strong>Explanation:</strong></p>
+
+<p><strong><img alt="" data-darkreader-inline-bgcolor="" data-darkreader-inline-bgimage="" src="https://assets.leetcode.com/uploads/2024/06/19/screenshot-2024-05-28-183907.png" style="width: 150px; height: 150px; padding: 10px; background: rgb(255, 255, 255); border-radius: 0.5rem; --darkreader-inline-bgimage: initial; --darkreader-inline-bgcolor: #181a1b;" /></strong></p>
+
+<p>Alternating groups:</p>
+
+<p><img alt="" data-darkreader-inline-bgcolor="" data-darkreader-inline-bgimage="" src="https://assets.leetcode.com/uploads/2024/06/19/screenshot-2024-05-28-184128.png" style="width: 150px; height: 150px; padding: 10px; background: rgb(255, 255, 255); border-radius: 0.5rem; --darkreader-inline-bgimage: initial; --darkreader-inline-bgcolor: #181a1b;" /><img alt="" data-darkreader-inline-bgcolor="" data-darkreader-inline-bgimage="" src="https://assets.leetcode.com/uploads/2024/06/19/screenshot-2024-05-28-184240.png" style="width: 150px; height: 150px; padding: 10px; background: rgb(255, 255, 255); border-radius: 0.5rem; --darkreader-inline-bgimage: initial; --darkreader-inline-bgcolor: #181a1b;" /></p>
+</div>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<div class="example-block">
+<p><strong>Input:</strong> <span class="example-io">colors = [1,1,0,1], k = 4</span></p>
+
+<p><strong>Output:</strong> <span class="example-io">0</span></p>
+
+<p><strong>Explanation:</strong></p>
+
+<p><img alt="" data-darkreader-inline-bgcolor="" data-darkreader-inline-bgimage="" src="https://assets.leetcode.com/uploads/2024/06/19/screenshot-2024-05-28-184516.png" style="width: 150px; height: 150px; padding: 10px; background: rgb(255, 255, 255); border-radius: 0.5rem; --darkreader-inline-bgimage: initial; --darkreader-inline-bgcolor: #181a1b;" /></p>
+</div>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>3 &lt;= colors.length &lt;= 10<sup>5</sup></code></li>
+	<li><code>0 &lt;= colors[i] &lt;= 1</code></li>
+	<li><code>3 &lt;= k &lt;= colors.length</code></li>
+</ul>

3483-alternating-groups-ii/solution.py

@@ -0,0 +1,35 @@
+# Approach 1: Expanding the Array & Sliding Window
+
+# Time: O(n + k)
+# Space: O(k)
+
+class Solution:
+    def numberOfAlternatingGroups(self, colors: List[int], k: int) -> int:
+        # Expand the array for cirular sequences
+        for i in range(k - 1):
+            colors.append(colors[i])
+
+        length = len(colors)
+        result = 0
+        left, right = 0, 1
+
+        while right < length:
+            # Check if the current color is the same as the last one
+            if colors[right] == colors[right - 1]:
+
+                # Pattern breaks, reset window from the current position
+                left = right
+                right += 1
+                continue
+
+            right += 1
+
+            if right - left < k:
+                continue
+
+            result += 1
+            left += 1
+
+        return result
+
+