Stack

Calculate how much rain water can be trapped between bars

Compare two strings with backspace characters (#)

Check whether every opening bracket is closed in the correct order

Design a stack that supports getMin in constant time

Evaluate an expression in Reverse Polish Notation

For each day, find how many days until a warmer temperature

Find next greater element for each value in nums1 based on nums2

Find next greater element in a circular array

Find the largest rectangle area in a histogram

Count how many car fleets arrive at the target

Simplify an absolute Unix-style file path

Remove k digits from a number string to produce the smallest possible number

Decode nested repetition patterns like 3[a2[c]]

Evaluate expression with +, -, *, / and non-negative integers