AKBAR  Akbar , The great
All of us are familiar with the reign of the great mughal ruler , Akbar. He was always concerned with the prosperity and safety of the people . Therefore to safeguard his kingdom (which consisted of N cities) he wanted to place secret soldiers all over his kingdom so as to protect the people . But since his kingdom is very large therefore he wanted to place them in such a way that every city is protected by one and only one soldier.According to Akbar , this is the optimum placement.
As for these soldiers they can protect multiple cities according to their strengths.
The strength of a particular soldier is defined as the maximum distance upto which a guard can protect a city from its base city(base city is the city assigned to the guard). If there are 3 cities C1, C2 and C3 such that C1 C2 and C2 C3 are connected respectively, if a soldier with strength 1 is placed at C2 then all the cities C1, C2 and C3 are protected by that soldier.
Also the kingdom is connected with a network of secret two way roads for faster access only accessible to these soldiers. The length of any road on this network between any two cities is 1 kms .There are R such roads in the kingdom.
He had given this task to birbal to place the soldiers . Birbal didn't wanted to be a fool in front of the king , therefore took the job and placed M soldiers all over the kingdom but he was not very good at mathematics . But since he is very intelligent he somehow places the guards all over the kingdom and now turns to you (who is a genius mathematician ;) ) to check whether his placements are good or not.
Your task is to check if the placements of the soldiers are optimum or not.
INPUT
The input consists of T test cases . Each test case then consists of 3 parts.The first line consists of N, R and M.
the next R lines consists of two numbers A and B denoting the two cities between which a road exists .
the next M lines consists of 2 numbers, city number K and strength S of that particular soldier.
=> strength 0 means it will only guard the city on which it is present .
=> assume every city is accesible from every other city .
CONSTRAINTS
T <= 10;
1 <= N <= 10^6;
N 1 <= R <= min( 10^7 , ( N * (N  1) ) / 2) );
1 <= K <= N;
0 <= S <= 10^6
OUTPUT
print "Yes" if the soldiers are placed optimumly else print "No". (quotes are for clarity)
SAMPLE INPUT
2
3 2 2
1 2
2 3
1 2
2 0
4 5 2
1 4
1 2
1 3
4 2
3 4
2 1
3 0
SAMPLE OUTPUT
No
Yes
WARNING ==> Large input.
hide comments
als1510:
20210410 18:14:08
I can't be able to understand the first test case . if first city's soldier has strength 2 then he can also protect the remaining two nodes. So why ita answer is "NO" 

abhinandan824:
20210401 09:20:51
Please can somebody explain the solution. I am stuck now and can't find any method. I have used dfs for finding k nearest neighbor and maintaining a vis array which I am incrementing and after doing dfs for all soldiers nodes. and after that checking if at any node vis[i] is greater than 1 or equal to 0 because a node can't be unprotected or protected by more than 1 soldier 

sayskar:
20210322 08:58:34
dfs works !! just need to keep track of parent 

vivek_prime:
20210303 12:32:01
i think they are accepting wrong solutions


pal550:
20210221 18:58:36
Test Cases are very Weak. Many accepted Solutions are not holistically correct.


csdeshpande19:
20210217 19:32:39
AC!


ashutosh_coder:
20210122 15:52:29
*one and only one*


izaj:
20201203 18:20:31
Weak Online Judge


paritosh99:
20201116 22:38:14
Got tle in first try when used visited array to check cycles, AC in second go when used set to keep track of visited vertices for checking of cycles. 

atul_pandey:
20201110 11:54:04
Copy and paste will make you a great coder like me! Last edit: 20201111 00:21:57 
Added by:  Prayank Mathur 
Date:  20141012 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All 
Resource:  own 