Game on Tree Easy
A rooted tree has n nodes numbered from 0 to n-1, with root at node 0. Each node i contains some number of stones (zero or more). Two players alternate turns. On each turn, a player picks a node that has at least one stone, takes exactly one stone from it, and moves that stone to the node's parent. Stones that reach the root are removed from play. The player who makes the last move — moving the final stone to the root — wins. Both players play optimally. Determine whether the first player can force a win.