Checklist

Is this ?

• Binary Search on the answer
• Meet in the Middle
• Super greedy (make a wild guess)

Thinking about solution

• Immediately play with the sample cases, you may have understood the problem wrong
• Think about constraints

Before Submitting

• Even if the test cases pass, make sure your code is at least doing something
• If the test cases are too simple, come up with an extra one
• Check constants are big enough
• Check time and memory limits
• Submit the right file

General

• #define int long long
• Fast IO
• Be very careful when copy pasting, check you've changed everything that needs changing
• Be wary of special cases, and when you do define one, be very sure you've correctly identified the full extent of their implications

STL

• Check for empty when calling .back(), .front(), .top() on containers
• Don't change a container as you iterate through it (accessing a map may change it)
• Always make sure your iterators are valid
• When using multiset, don't use erase when you want to erase one!!!

Graphs

• Add edges both ways if the graph is bidirectional
• On problems where you remove stuff, just do it backwards.

Beecrowd/UVa

• Don't put space at the end of output
• Check if there are multiple testcases

DP

• Try to invert the order of the states - sometimes the problem becomes much easier
• Can you use D&C DP?
• Can you use Convex Hull Trick?

Games

• Sprague-Grundy
• Symmetry
• Code something that calculates for small cases and find a pattern