F: Fred’s Lotto Tickets

November 23rd, 2009 | Categories: 2008 Regionals

This was the simplest problem in the set. It was originally going to be one of the practice problems, but when one of the judged got confused about Combination Lock, we knew we needed something easier, and Lotto got promoted.

Here’s the Judge Input, the Judge Output, the main solving program, another Java program, and a C++ program.

If you really need it, there’s a solution outlined in the spoiler.

Spoiler »

You can completely ignore the concept of “tickets” – just read in 6n numbers. Java’s Scanner will do this easily, and I believe C++’s cin will as well. You’re just making life harder on yourself if you’re reading a whole line and then parsing it into 6 integers.

You can just keep a boolean array and count the trues – say Yes if there are 49 of them – or, just keep a set (like Java’s HashSet). Shove the numbers into a set as you read them, and at the and, say “Yes” if the set has 49 elements.

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