Sync LeetCode submission Runtime - 280 ms (83.33%), Memory - 96.2 MB (5.56%)

Author: jimit105

3219-make-lexicographically-smallest-array-by-swapping-elements/README.md

@@ -0,0 +1,49 @@
+<p>You are given a <strong>0-indexed</strong> array of <strong>positive</strong> integers <code>nums</code> and a <strong>positive</strong> integer <code>limit</code>.</p>
+
+<p>In one operation, you can choose any two indices <code>i</code> and <code>j</code> and swap <code>nums[i]</code> and <code>nums[j]</code> <strong>if</strong> <code>|nums[i] - nums[j]| &lt;= limit</code>.</p>
+
+<p>Return <em>the <strong>lexicographically smallest array</strong> that can be obtained by performing the operation any number of times</em>.</p>
+
+<p>An array <code>a</code> is lexicographically smaller than an array <code>b</code> if in the first position where <code>a</code> and <code>b</code> differ, array <code>a</code> has an element that is less than the corresponding element in <code>b</code>. For example, the array <code>[2,10,3]</code> is lexicographically smaller than the array <code>[10,2,3]</code> because they differ at index <code>0</code> and <code>2 &lt; 10</code>.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [1,5,3,9,8], limit = 2
+<strong>Output:</strong> [1,3,5,8,9]
+<strong>Explanation:</strong> Apply the operation 2 times:
+- Swap nums[1] with nums[2]. The array becomes [1,3,5,9,8]
+- Swap nums[3] with nums[4]. The array becomes [1,3,5,8,9]
+We cannot obtain a lexicographically smaller array by applying any more operations.
+Note that it may be possible to get the same result by doing different operations.
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [1,7,6,18,2,1], limit = 3
+<strong>Output:</strong> [1,6,7,18,1,2]
+<strong>Explanation:</strong> Apply the operation 3 times:
+- Swap nums[1] with nums[2]. The array becomes [1,6,7,18,2,1]
+- Swap nums[0] with nums[4]. The array becomes [2,6,7,18,1,1]
+- Swap nums[0] with nums[5]. The array becomes [1,6,7,18,1,2]
+We cannot obtain a lexicographically smaller array by applying any more operations.
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [1,7,28,19,10], limit = 3
+<strong>Output:</strong> [1,7,28,19,10]
+<strong>Explanation:</strong> [1,7,28,19,10] is the lexicographically smallest array we can obtain because we cannot apply the operation on any two indices.
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
+	<li><code>1 &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
+	<li><code>1 &lt;= limit &lt;= 10<sup>9</sup></code></li>
+</ul>

3219-make-lexicographically-smallest-array-by-swapping-elements/solution.py

@@ -0,0 +1,36 @@
+# Approach: Sorting + Grouping
+
+# Time: O(n * log n)
+# Space: O(n)
+
+from collections import deque
+
+class Solution:
+    def lexicographicallySmallestArray(self, nums: List[int], limit: int) -> List[int]:
+        nums_sorted = sorted(nums)
+
+        curr_group = 0
+        num_to_group = {}
+        num_to_group[nums_sorted[0]] = curr_group
+
+        group_to_list = {}
+        group_to_list[curr_group] = deque([nums_sorted[0]])
+        
+        for i in range(1, len(nums)):
+            if abs(nums_sorted[i] - nums_sorted[i - 1]) > limit:
+                # new group
+                curr_group += 1
+
+            num_to_group[nums_sorted[i]] = curr_group
+
+            if curr_group not in group_to_list:
+                group_to_list[curr_group] = deque()
+            group_to_list[curr_group].append(nums_sorted[i])
+
+        # Iterate through the input and overwrite each element with the next element in its corresponding group
+        for i in range(len(nums)):
+            num = nums[i]
+            group = num_to_group[num]
+            nums[i] = group_to_list[group].popleft()
+
+        return nums