#P2033. The xor-longest Path

The xor-longest Path

Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 7214 Accepted: 1536 Description In an edge-weighted tree, the xor-length of a path p is defined as the xor sum of the weights of edges on p: ⊕ is the xor operator. We say a path the xor-longest path if it has the largest xor-length. Given an edge-weighted tree with n nodes, can you find the xor-longest path? Input The input contains several test cases. The first line of each test case contains an integer n(1<=n<=100000), The following n-1 lines each contains three integers u(0 <= u < n),v(0 <= v < n),w(0 <= w < 2^31), which means there is an edge between node u and v of length w. Output For each test case output the xor-length of the xor-longest path. Sample Input 4 0 1 3 1 2 4 1 3 6 Sample Output 7 Hint The xor-longest path is 0->1->2, which has length 7 (=3 ⊕ 4) Source