Apr 25

Author: siddydutta

2025-04-April-LeetCoding-Challenge/Count of Interesting Subarrays.py

@@ -0,0 +1,27 @@
+class Solution:
+    def countInterestingSubarrays(self, nums: list[int], modulo: int, k: int) -> int:
+        count, prefix = 0, 0
+        freqs = {0: 1}
+        for num in nums:
+            if num % modulo == k:
+                prefix = (prefix + 1) % modulo
+            target = (prefix - k + modulo) % modulo
+            count += freqs.get(target, 0)
+            freqs[prefix] = freqs.get(prefix, 0) + 1
+        return count
+
+
+def main():
+    nums = [3, 2, 4]
+    modulo = 2
+    k = 1
+    assert Solution().countInterestingSubarrays(nums, modulo, k) == 3
+
+    nums = [3, 1, 9, 6]
+    modulo = 3
+    k = 0
+    assert Solution().countInterestingSubarrays(nums, modulo, k) == 2
+
+
+if __name__ == '__main__':
+    main()

2025-04-April-LeetCoding-Challenge/README.md

@@ -28,7 +28,7 @@
 | April 22 | [2338. Count the Number of Ideal Arrays](https://leetcode.com/problems/count-the-number-of-ideal-arrays/) | Hard | Unsolved |
 | April 23 | [1399. Count Largest Group](https://leetcode.com/problems/count-largest-group/) | Easy | Solved |
 | April 24 | [2799. Count Complete Subarrays in an Array](https://leetcode.com/problems/count-complete-subarrays-in-an-array/) | Medium | Solved |
-| April 25 | []() |  |  |
+| April 25 | [2845. Count of Interesting Subarrays](https://leetcode.com/problems/count-of-interesting-subarrays/) | Medium | Unsolved |
 | April 26 | []() |  |  |
 | April 27 | []() |  |  |
 | April 28 | []() |  |  |
@@ -40,5 +40,5 @@
 | Level  | Problems | Solved | Unsolved |
 | ---    | --- | --- | --- |
 | Easy   | 7 | 7 | 0 |
-| Medium | 13 | 10 | 3 |
+| Medium | 13 | 9 | 4 |
 | Hard   | 4 | 0 | 4 |