TopCoder problem "ToolsBox" used in SRM 453.5 (Division II Level One)

Problem Statement

You are a carpenter and you want to build several pieces of furniture. Unfortunately, you've lost all your tools. You are given a String[] need, the i-th element of which is a space separated list of the tools required to construct the i-th piece of furniture. Return the number of different tools you must buy to construct all the furniture.

Definition

Class:	ToolsBox
Method:	countTools
Parameters:	String[]
Returns:	int
Method signature:	int countTools(String[] need)
(be sure your method is public)

Constraints

need will contain between 1 and 50 elements, inclusive.

Each element of need will contain between 1 and 50 characters, inclusive.

Each element of need will contain only uppercase letters ('A'-'Z') and spaces (' ').

Each element of need will contain no leading, trailing, or consecutive spaces.

For each element of need, all tool names in it will be distinct.

Examples

{"SAW HAMMER SCREWDRIVER","SCREWDRIVER HAMMER KNIFE"}

Returns: 4

You need four tools: "SAW", "HAMMER", "SCREWDRIVER" and "KNIFE".

{"SAW"}

Returns: 1

You need only "SAW".

{"SAW","SAW"}

Returns: 1

Now you want to build two furniture items, but you need only "SAW" for both of them.

Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=10461

Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=14174&pm=10461

Writer:

andrewzta

Testers:

PabloGilberto , ivan_metelsky , Vasyl[alphacom]