April (US Open) 2014 Silver Problem 1: Fair Photography

Result: 6/10 *****t*ttt

I'm not sure how to implement this faster.

fairphoto.cpp

February 2014 Bronze Problem 1: Mirror Field

Result: 8/10 **x*x*****

This is actually more difficult than Problem 2, which I completed first.

mirror.cpp

January 2014 Bronze Problem 1: Ski Course Design

Result: 10/10 **********

My solution is O(N^2), but up to 83*99 iterations.

skidesign.cpp

December 2013 Bronze Problem 1: Record Keeping

Result: 10/10 **********

As long as there aren't any hash collisions, this is a fast solution.

records.cpp

November 2013 Bronze (Correction 2) Problem 1: Combination Lock

Result: 10/10 **********

This is more optimized than my previous correction though still in O(1) time.

combo2.cpp

November 2013 Bronze (Correction) Problem 1: Combination Lock

Result: 10/10 **********

Upon review, I beat the solution! Though N is no larger than 100, my solution runs in O(1) time and theirs runs in O(N^3) time.

combo2.cpp

November 2013 Bronze Problem 1: Combination Lock

Result: 4/10 *x*xxxx**x

I optimized it near the end, but then I realized that the overlap() function fails when N < 5.

combo.cpp

February 2013 Bronze Problem 1: Message Relay

Result: 10/10 **********

relay.cpp

December 2012 Bronze Problem 1: Meet and Greet

Result: 10/10 **********

November 2012 Bronze Problem 1: Find the Cow!

The contest has ended! I have posted the first solution now.
Result: 9/10 *********t (timeout)
cowfind.cpp