May 29

Author: siddydutta

2025-05-May-LeetCoding-Challenge/Maximize the Number of Target Nodes After Connecting Trees II.py

@@ -0,0 +1,58 @@
+from collections import deque
+
+
+class Solution:
+    def __init__(self):
+        self.even_1, self.odd_1 = 0, 0
+        self.even_2, self.odd_2 = 0, 0
+
+    def __build_adj_list(self, edges: list[list[int]]) -> list[list[int]]:
+        n = len(edges) + 1
+        graph = [[] for _ in range(n)]
+        for u, v in edges:
+            graph[u].append(v)
+            graph[v].append(u)
+        return graph
+
+    def __bfs_colour(self, graph: list[list[int]], colour: list[int], flag: bool):
+        queue = deque([0])
+        colour[0] = 0
+        while queue:
+            u = queue.popleft()
+            if colour[u] == 0:
+                if flag:
+                    self.even_1 += 1
+                else:
+                    self.even_2 += 1
+            else:
+                if flag:
+                    self.odd_1 += 1
+                else:
+                    self.odd_2 += 1
+            for v in graph[u]:
+                if colour[v] == -1:
+                    colour[v] = colour[u] ^ 1
+                    queue.append(v)
+
+    def maxTargetNodes(self, edges1: list[list[int]], edges2: list[list[int]]) -> list[int]:
+        graph1, graph2 = map(self.__build_adj_list, (edges1, edges2))
+        colour_1, colour_2 = [-1] * len(graph1), [-1] * len(graph2)
+        self.__bfs_colour(graph1, colour_1, True)
+        self.__bfs_colour(graph2, colour_2, False)
+        max_target2 = max(self.even_2, self.odd_2)
+        return [(self.even_1 if colour_1[node] == 0 else self.odd_1) + max_target2
+                for node in range(len(graph1))]
+
+
+def main():
+    edges1 = [[0, 1], [0, 2], [2, 3], [2, 4]]
+    edges2 = [[0, 1], [0, 2], [0, 3], [2, 7], [1, 4], [4, 5], [4, 6]]
+    assert Solution().maxTargetNodes(edges1, edges2) == [8, 7, 7, 8, 8]
+
+    edges1 = [[0, 1], [0, 2], [0, 3], [0, 4]]
+    edges2 = [[0, 1], [1, 2], [2, 3]]
+    assert Solution().maxTargetNodes(edges1, edges2) == [3, 6, 6, 6, 6]
+
+
+if __name__ == '__main__':
+    main()

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

@@ -32,7 +32,7 @@
 | May 26 | [1857. Largest Color Value in a Directed Graph](https://leetcode.com/problems/largest-color-value-in-a-directed-graph/) | Hard | Unsolved |
 | May 27 | [2894. Divisible and Non-divisible Sums Difference](https://leetcode.com/problems/divisible-and-non-divisible-sums-difference/) | Easy | Solved |
 | May 28 | [3372. Maximize the Number of Target Nodes After Connecting Trees I](https://leetcode.com/problems/maximize-the-number-of-target-nodes-after-connecting-trees-i/) | Medium | Solved |
-| May 29 | []() |  |  |
+| May 29 | [3373. Maximize the Number of Target Nodes After Connecting Trees II](https://leetcode.com/problems/maximize-the-number-of-target-nodes-after-connecting-trees-ii/) | Hard | Unsolved |
 | May 30 | [2359. Find Closest Node to Given Two Nodes](https://leetcode.com/problems/find-closest-node-to-given-two-nodes/) | Medium | Solved |
 | May 31 | []() |  |  |
 
@@ -42,4 +42,4 @@
 | ---    | --- | --- | --- |
 | Easy   | 7 | 7 | 0 |
 | Medium | 15 | 12 | 3 |
-| Hard   | 6 | 1 | 5 |
+| Hard   | 7 | 1 | 6 |