[LeetCode Sync] Runtime - 668 ms (17.70%), Memory - 151.6 MB (18.18%)

Author: NamVr

2434-design-a-number-container-system/README.md

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+<p>Design a number container system that can do the following:</p>
+
+<ul>
+	<li><strong>Insert </strong>or <strong>Replace</strong> a number at the given index in the system.</li>
+	<li><strong>Return </strong>the smallest index for the given number in the system.</li>
+</ul>
+
+<p>Implement the <code>NumberContainers</code> class:</p>
+
+<ul>
+	<li><code>NumberContainers()</code> Initializes the number container system.</li>
+	<li><code>void change(int index, int number)</code> Fills the container at <code>index</code> with the <code>number</code>. If there is already a number at that <code>index</code>, replace it.</li>
+	<li><code>int find(int number)</code> Returns the smallest index for the given <code>number</code>, or <code>-1</code> if there is no index that is filled by <code>number</code> in the system.</li>
+</ul>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input</strong>
+[&quot;NumberContainers&quot;, &quot;find&quot;, &quot;change&quot;, &quot;change&quot;, &quot;change&quot;, &quot;change&quot;, &quot;find&quot;, &quot;change&quot;, &quot;find&quot;]
+[[], [10], [2, 10], [1, 10], [3, 10], [5, 10], [10], [1, 20], [10]]
+<strong>Output</strong>
+[null, -1, null, null, null, null, 1, null, 2]
+
+<strong>Explanation</strong>
+NumberContainers nc = new NumberContainers();
+nc.find(10); // There is no index that is filled with number 10. Therefore, we return -1.
+nc.change(2, 10); // Your container at index 2 will be filled with number 10.
+nc.change(1, 10); // Your container at index 1 will be filled with number 10.
+nc.change(3, 10); // Your container at index 3 will be filled with number 10.
+nc.change(5, 10); // Your container at index 5 will be filled with number 10.
+nc.find(10); // Number 10 is at the indices 1, 2, 3, and 5. Since the smallest index that is filled with 10 is 1, we return 1.
+nc.change(1, 20); // Your container at index 1 will be filled with number 20. Note that index 1 was filled with 10 and then replaced with 20. 
+nc.find(10); // Number 10 is at the indices 2, 3, and 5. The smallest index that is filled with 10 is 2. Therefore, we return 2.
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= index, number &lt;= 10<sup>9</sup></code></li>
+	<li>At most <code>10<sup>5</sup></code> calls will be made <strong>in total</strong> to <code>change</code> and <code>find</code>.</li>
+</ul>

2434-design-a-number-container-system/solution.py

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+class NumberContainers:
+
+    def __init__(self):
+        # Initializing the defaultdict with SortedSet and the regular dictionary
+        # Map from number to set of indices
+        self.number_to_indices = collections.defaultdict(SortedSet)
+        # Map from index to number
+        self.index_to_number = {}
+
+    def change(self, index: int, number: int) -> None:
+        # If index already has a number, remove it from the old number's index set
+        if index in self.index_to_number:
+            previous_number = self.index_to_number[index]
+            self.number_to_indices[previous_number].remove(index)
+            if not self.number_to_indices[previous_number]:
+                del self.number_to_indices[previous_number]
+
+        # Update the number and add the index to the new number's set
+        self.index_to_number[index] = number
+        self.number_to_indices[number].add(index)
+
+    def find(self, number: int) -> int:
+        # Return the smallest index for the given number, or -1 if not found
+        if number in self.number_to_indices and self.number_to_indices[number]:
+            return self.number_to_indices[number][0]
+        return -1
+
+
+# Your NumberContainers object will be instantiated and called as such:
+# obj = NumberContainers()
+# obj.change(index,number)
+# param_2 = obj.find(number)