E. Mahmoud and Ehab and the xor-MST
bitmasks; dp; graphs; implementation; math
Ehab is interested in the bitwise-xor operation and the special graphs. Mahmoud gave him a problem that combines both. He has a complete graph consisting of n vertices numbered from 0 to n - 1. For all 0 ≤ u < v < n, vertex u and vertex v are connected with an undirected edge that has weight (where is the bitwise-xor operation). Can you find the weight of the minimum spanning tree of that graph?You can read about complete graphs in https://en.wikipedia.org/wiki/Complete_graphYou can read about the minimum spanning tree in https://en.wikipedia.org/wiki/Minimum_spanning_treeThe weight of the minimum spanning tree is the sum of the weights on the edges included in it.
The only line contains an integer n (2 ≤ n ≤ 1012), the number of vertices in the graph.
The only line contains an integer x, the weight of the graph's minimum spanning tree.
In the first sample: The weight of the minimum spanning tree is 1+2+1=4.