de Morgan's laws but epic More on reddit.com

Here are some good & brief puzzles that can usually be solved in about the time it takes to drink a cup of coffee: http://www.datagenetics.com/blog/june22014/index.html Actually, many of the rest of the posts at datagenetics might provide some material for good challenges (the one about distributing passwords will open their eyes to the possibilities of polynomials!): http://www.datagenetics.com/blog.html Martin Gardner's Aha! Gotcha! (about paradoxes) and Aha! Insight! (about finding simpler ways to solve complex problems) is another good source of the type of puzzles you're seeking (especially the latter). There's also: MindYourDecision.com's Sunday Puzzles - Try springing the evil geometry puzzle on them! James Tanton's Curriculum Inspirations - Don't miss the video archive ! More on reddit.com

double ceil(double a) { auto b = double((long long)a); if (a < 0 || b == a) { return b; } else { return b+1; } } EDIT: fixed negative number behavior and casted to larger to integral type per u/bad_investor13 More on reddit.com

u/Nitropanel - Your post was submitted successfully. Once your problem is solved, reply to the answer(s) saying Solution Verified to close the thread. Follow the submission rules -- particularly 1 and 2. To fix the body, click edit. To fix your title, delete and re-post. Include your Excel version and all other relevant information Failing to follow these steps may result in your post being removed without warning. I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns. More on reddit.com