Summer Camp-Basic graph theory

	5/37	Problem A	HUST 1019	A Dangerous Trip
	10/71	Problem B	HUST 1631	Road System
		Problem C	Uvalive 3523	Knights of the Round Table
	1/5	Problem D	Uvalive 5135	Mining Your Own Business
	1/1	Problem E	Uvalive 4287	Proving equivalences
	0/2	Problem F	Gym 100216E	Shortest Path
		Problem G	POJ 3177	Redundant Paths
		Problem H	POJ 1236	Network of schools
		Problem I	URAL 1752	Tree 2
	5/5	Problem J	POJ 1330	Nearest Common Ancestors
	4/16	Problem K	POJ 1470	Closest Common Ancestors

A

To shorten the shortest path by half.

Two different methods. 1. First, the shortest starting point, each side of the reverse and then seek the end of the. Then enumerate each edge binary to find out the answer. 2. Consider each point as two points, the original is divided into two layers, if a to B has a weight of the side of C, then A to B ' has a C/2 side, so that the shortest time to do is the answer. Note that the edge is an integer, but the answer may be a decimal, preferably the edge.

B

Bare minimum spanning tree.

C

Knights of the Round Table, classic questions, not yet done.

D

The miner at the bottom.

E

Equivalence proof, to a given graph, ask at least how many edges of the programming strong connected graph.

The strongly connected components are then shrunk to a point, since they are already equal to each other. Then, according to the processed figure, the total and total degree of the graph is calculated, and the larger value is the answer.

F

Do once SPFA, if encountered negative ring on the DFS over this point, then the point of traversal is not the shortest, marked '-'. The final output can be.

I don't know what's wrong with my code.

J,k

Bare LCA.

　　

Summer Camp-Basic graph theory