PROBLEM STATEMENT
When the Christmas dinner is over, it's time to sing carols. Unfortunately, not all the family
members know the lyrics to the same carols. Everybody knows at least one, though.
You are given a vector lyrics. The j-th character of the i-th element of lyrics is 'Y'
if the i-th person knows the j-th carol, and 'N' if he doesn't. Return the minimal number of
carols that must be sung to allow everyone to sing at least once.
DEFINITION
Class:CarolsSinging
Method:choose
Parameters:vector
Returns:int
Method signature:int choose(vector lyrics)
CONSTRAINTS
-lyrics will contain between 1 and 30 elements, inclusive.
-Each element of lyrics will contain between 1 and 10 characters, inclusive.
-Each element of lyrics will contain the same number of characters.
-Each element of lyrics will contain only 'Y' and 'N' characters.
-Each element of lyrics will contain at least one 'Y' character.
EXAMPLES
0)
{"YN","NY"}
Returns: 2
Both carols need to be sung.
1)
{"YN","YY","YN"}
Returns: 1
Everybody knows the first carol, so singing just that one is enough.
2)
{"YNN","YNY","YNY","NYY","NYY","NYN"}
Returns: 2
Singing the best known carol is not always the optimal strategy. Here, the optimal way is to pick
the first two carols even though four people know the third one.
3)
{"YNNYYY","YYNYYY","YNNYYN","NYYNNN","YYYNNN","YYYNNY","NYYYYY","NYNYYY","NNNNYY",
"YYYYYY","YNNNNN","YYYYNY","YYNNNN","NNYYYN","NNNNYY","YYYNNN","NYNNYN","YNNYYN",
"YYNNNY","NYYNNY","NNYYYN","YNYYYN","NNNYNY","YYYYNN","YYNYNN","NYYNYY","YYNYYN"}
Returns: 4
This problem statement is the exclusive and proprietary property of TopCoder, Inc. Any
unauthorized use or reproduction of this information without the prior written consent of
TopCoder, Inc. is strictly prohibited. (c)2010, TopCoder, Inc. All rights reserved.
This problem statement is the exclusive and proprietary property of TopCoder, Inc. Any unauthorized use or reproduction of this information without the prior written consent of TopCoder, Inc. is strictly prohibited. (c)2010, TopCoder, Inc. All rights reserved.