Count the number of different ways to reach the top of a staircase if you can take 1 or 2 steps at a time.
Pick non-adjacent houses to rob so the total money is maximized.
Find the fewest coins needed to make a given amount of money, or say it is impossible.
Find the longest chain of numbers in an array that are strictly increasing (not necessarily adjacent).
Pack a bag with items of different weights and values to maximize total value without going over the weight limit.
Find the cheapest path from the top-left to the bottom-right of a grid, moving only right or down.
Find the fewest edits (insert, delete, or replace a character) to turn one word into another.
Count how many valid letter-decodings a string of digits can have, where 1-26 each map to A-Z.