##### ###### ##### ### # # ### # # ###### ## ## ## ## ## ## ## # # # # # ## ##### #### ##### # # # # # # # #### ## # ## ## ## ## # # # # # ## ## # ###### ## ### # ### # ######
##### ###### ##### ### # # ### # # ###### ## ## ## ## ## ## ## # # # # # ## ##### #### ##### # # # # # # # #### ## # ## ## ## ## # # # # # ## ## # ###### ## ### # ### # ######
Euler tour application
Given a tree with nodes, each with a value. Process queries:
Update: change node 's value to
Query: return the sum of values in 's subtree Constraints: . You've found the perfect Euler tour problem. Subtree becomes a range. Point update on node becomes point update on tour. Subtree sum becomes range sum.
