luogu#P3556. [POI2013] MOR-Tales of seafaring

[POI2013] MOR-Tales of seafaring

题目描述

Young Bytensson loves to hang out in the port tavern, where he often listens to the sea dogs telling their tales of seafaring.

Initially, he believed them all, however incredible they sounded.

Over time though, he became suspicious.

He has decided to write a program that will verify if there may be any grain of truth in those tall stories.

Bytensson reasoned that while he cannot tell if the sailors indeed weathered all those storms, he can at least find out if their travel itineraries make sense.

This is a task for a programmer, which Bytensson, unfortunately, is not.

Help him out!

There are nn ports and mm waterways connecting them in the waters frequented by the sailors Bytensson listened to.

If there is a waterway between two ports, then sailing from one to the other is possible. Any waterway can be sailed in both directions.

Bytensson got to know kk seafaring tales.

Each tells of a sailor who began his journey in one port, sailed a number of waterways, and ended up in another port, which may have been the one he initially set sail from.

The sailor in question may have sailed through the same waterway many times, each time in any direction.

给n个点m条边无向图,每次询问两个点之间是否有长度为d的路径(不一定是简单路径)

输入格式

In the first line of the standard input, there are three integers, nn,mm and kk (2n5 0002\le n\le 5\ 000, 1m5 0001\le m\le 5\ 000, 1k1 000 0001\le k\le 1\ 000\ 000).

These denote, respectively: the number of ports in the waters frequented by the sailors who told Bytensson their stories,the number of waterways, and the number of tales.

The mm lines that follow specify the waterways.

A single waterway's description consists of a single line that contains two integers, aa and bb (1a,bn1\le a,b\le n,aba\ne b), separated by a single space; these specify the numbers of ports at the two ends of this particular waterway.

The kk lines that follow specify the tales that Bytensson has heard. A single tale's description consists of a single line with three integers,ss,tt,and dd (1s,tn1\le s,t\le n,1d1 000 000 0001\le d\le 1\ 000\ 000\ 000 ), separated by single spaces. These indicate that the tale's protagonist set sail from port no. ss , ended the journey in port no. tt , and sailed exactly dd times through various waterways.

输出格式

Your program should print exactly kk lines to the standard output; the ii-th of them should contain the word TAK (Polish for yes) if the journey described in the ii-th tale(in input order) could have taken place.

If it could not, then the line should contain the word NIE (Polish for no).

8 7 4
1 2
2 3
3 4
5 6
6 7
7 8
8 5
2 3 1
1 4 1
5 5 8
1 8 10

TAK
NIE
TAK
NIE

提示

给n个点m条边无向图,每次询问两个点之间是否有长度为d的路径(不一定是简单路径)