Stack is a container of objects that are inserted and removed according to the last-in-first-out (LIFO) principle. Queue is a container of objects (a linear collection) that are inserted and removed according to the first-in-first-out (FIFO) principle.
Brackets
Determine whether a given string of parentheses (multiple types) is properly nested.
Difficulty Level: Easy
Fish
N voracious fish are moving along a river. Calculate how many fish are alive.
Difficulty Level: Easy
Nesting
Determine whether a given string of parentheses (single type) is properly nested.
Difficulty Level: Easy