Where Stacks Shine

Stacks appear whenever you need to remember something and then process it in reverse order:

$1.$ Parentheses matching: push opens, pop on closes

$2.$ Expression evaluation: handle operators and operands

$3.$ Undo functionality: push actions, pop to undo

$4.$ DFS traversal: iterative depth-first search

$5.$ Call stack: how recursion works

Whenever you see "matching pairs" or "most recent unpaired element," think stack.