TFRIENDS - True Friends
You are given a string array representing Known people. Known[i][j]='Y' if i knows j.
Friends: A is a friend of B if B knows A or B has a friend who knows A.
True friends: A and B are true friends if A is a friend of B and B is a friend of A.
Group: Everyone in a Group must be true friends to each other.
Your task is to find the number of Groups from the given list of Known people. It can be proved that there is exactly only one possible way for forming the groups.
Input: The first line consists of an integer t, the number of test cases. For each test case, you are given an array of strings representing Known people. Known is of size NxN where N is the total number of people.
Output: For each test case, print the number of Groups.
Input Constraints:
1<=t<=1000
1<=N<=100
Known[i][j] is either 'Y' or 'N'
Known[i][i]='N' (Nobody knows themselves)
Sample Input:
3 3 NYN NNY YNN 7 NNYNNNN NNNYYYN NNNNNNN YNNNNNN NNNYNNN NNNNNNN NNNNNYN 7 NNNNYYN NNNNNNN NNNNNYN NYNNNYY NNNYNNN NNYNNNY NNNNYNN
Sample Output:
1 7 3
Explanation:
Case 1: All the friends are true friends to each other
Case 2: No two true friends exist.
Case 3: There are 3 groups of true friends. {0}, {1}, {2,3,4,5,6}
hide comments
Arjav:
2016-01-24 22:14:20
[spoiler]....:) Last edit: 2016-07-29 22:31:17 |
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varun yadav:
2015-11-04 11:57:19
Piece of cake,, without seeing any reference Last edit: 2015-11-04 11:57:52 |
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thenamesake:
2015-10-08 12:47:07
Simply find the [spoiler removed] Last edit: 2015-10-12 14:19:29 |
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nehaa:
2015-09-13 13:51:00
Hi, can anyone tell me the working approach of this question.. how to get tutorial or something |
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pk:
2015-08-05 09:13:39
O(n^3) giving tle
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Rohan Jain:
2015-05-14 11:48:13
@cegprakash if A is a friend of B, will that imply B knows A..? |
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sathyanarayanan:
2014-05-23 16:41:18
@cegprakash I know, you are the fan of these kind of problems!
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cegprakash:
2014-04-17 09:19:08
anurag garg : Is it that hard to write a test case generator and a tester code? |
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anurag garg:
2014-04-09 16:53:43
@author can you have a look at my submission id:11415247 and tell me whats wrong with my algorithm
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Added by: | cegprakash |
Date: | 2014-03-10 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: BF |