Trees DP on induced subgraphs of a tree Count Induced Subgraphs Code : Count Induced Subgraphs Induced Subgraphs with Fixed Degree Code : Induced Subgraphs with Fixed Degree Induced Subgraphs with Compressed Degree Code : Induced Subgraphs with Compressed Degree Prologue to Leaf Color Code : Prologue to Leaf Color DP on spanning subgraphs of a tree Count Spanning Subgraphs Code : Count Spanning Subgraphs Swap on Tree Code : Swap on Tree Sum of Degree Sum Code : Sum of Degree Sum DP on Trees Downward Path with Only Last Vertex Black Code : Downward Path with Only Last Vertex Black Paths with Terminal Black Vertices Code : Paths with Terminal Black Vertices Timer on Trees Ancestor Relation Code : Ancestor Relation Subtree Size Code : Subtree Size Subtree Sum Code : Subtree Sum Max Sum on Downward Path Code : Max Sum on Downward Path Happy Life in University Code : Happy Life in University