#826 · #3068 · Find the Maximum Sum of Node Values(最大节点价值之和)

You are given a tree with n nodes, an array nums of node values, an integer k, and edges describing the tree. In one operation, choose an edge and replace both endpoint values with their XOR by k. Maximise the sum of all node values. Constraints: 2 <= n <= 2 * 10^4, 1 <= nums[i], k <= 10^9.