May 04

Author: siddydutta

2025-05-May-LeetCoding-Challenge/Number of Equivalent Domino Pairs.py

@@ -0,0 +1,23 @@
+from collections import defaultdict
+
+
+class Solution:
+    def numEquivDominoPairs(self, dominoes: list[list[int]]) -> int:
+        counts = defaultdict(int)
+        pairs = 0
+        for domino in map(tuple, (map(sorted, dominoes))):
+            pairs += counts[domino]
+            counts[domino] += 1
+        return pairs
+
+
+def main():
+    dominoes = [[1, 2], [2, 1], [3, 4], [5, 6]]
+    assert Solution().numEquivDominoPairs(dominoes) == 1
+
+    dominoes = [[1, 2], [1, 2], [1, 1], [1, 2], [2, 2]]
+    assert Solution().numEquivDominoPairs(dominoes) == 3
+
+
+if __name__ == '__main__':
+    main()

2025-05-May-LeetCoding-Challenge/README.md

@@ -7,7 +7,7 @@
 | May 01 | [2071. Maximum Number of Tasks You Can Assign](https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign/) | Hard | Solved |
 | May 02 | [838. Push Dominoes](https://leetcode.com/problems/push-dominoes/) | Medium | Solved |
 | May 03 | [1007. Minimum Domino Rotations For Equal Row](https://leetcode.com/problems/minimum-domino-rotations-for-equal-row/) | Medium | Solved |
-| May 04 | []() |  |  |
+| May 04 | [1128. Number of Equivalent Domino Pairs](https://leetcode.com/problems/number-of-equivalent-domino-pairs/) | Easy | Solved |
 | May 05 | []() |  |  |
 | May 06 | []() |  |  |
 | May 07 | []() |  |  |
@@ -40,6 +40,6 @@
 ## Summary
 | Level  | Problems | Solved | Unsolved |
 | ---    | --- | --- | --- |
-| Easy   | 0 | 0 | 0 |
+| Easy   | 1 | 1 | 0 |
 | Medium | 2 | 2 | 0 |
 | Hard   | 1 | 1 | 0 |