Jul 06

Author: siddydutta

2025-07-July-LeetCoding-Challenge/Finding Pairs With a Certain Sum.py

@@ -0,0 +1,35 @@
+from collections import Counter
+
+
+class FindSumPairs:
+
+    def __init__(self, nums1: list[int], nums2: list[int]):
+        self.nums1 = nums1
+        self.nums2 = nums2
+        self.counts2 = Counter(nums2)
+
+    def add(self, index: int, val: int) -> None:
+        self.counts2[self.nums2[index]] -= 1
+        self.nums2[index] += val
+        self.counts2[self.nums2[index]] += 1
+
+    def count(self, tot: int) -> int:
+        result = 0
+        for n1 in self.nums1:
+            result += self.counts2[tot - n1]
+        return result
+
+
+def main():
+    obj = FindSumPairs([1, 1, 2, 2, 2, 3], [1, 4, 5, 2, 5, 4])
+    assert obj.count(7) == 8
+    obj.add(3, 2)
+    assert obj.count(8) == 2
+    assert obj.count(4) == 1
+    obj.add(0, 1)
+    obj.add(1, 1)
+    assert obj.count(7) == 11
+
+
+if __name__ == '__main__':
+    main()

2025-07-July-LeetCoding-Challenge/README.md

@@ -9,7 +9,7 @@
 | July 03 | [3304. Find the K-th Character in String Game I](https://leetcode.com/problems/find-the-k-th-character-in-string-game-i/) | Easy | Solved |
 | July 04 | [3307. Find the K-th Character in String Game II](https://leetcode.com/problems/find-the-k-th-character-in-string-game-ii/) | Hard | Unsolved |
 | July 05 | [1394. Find Lucky Integer in an Array](https://leetcode.com/problems/find-lucky-integer-in-an-array/) | Easy | Solved |
-| July 06 | []() |  |  |
+| July 06 | [1865. Finding Pairs With a Certain Sum](https://leetcode.com/problems/finding-pairs-with-a-certain-sum/) | Medium | Solved |
 | July 07 | []() |  |  |
 | July 08 | []() |  |  |
 | July 09 | []() |  |  |
@@ -41,5 +41,5 @@
 | Level  | Problems | Solved | Unsolved |
 | ---    | --- | --- | --- |
 | Easy   | 3 | 3 | 0 |
-| Medium | 0 | 0 | 0 |
+| Medium | 1 | 1 | 0 |
 | Hard   | 2 | 0 | 2 |