DSA · Theory

Design a stack that supports getMin() in O(1) time and O(1) extra space

Theory

725/810

Design a stack that supports getMin() in O(1) time and O(1) extra space

If you can teach Design a stack that supports getMin() in O(1) time and O(1) extra space using undo typing, you know it. If you only know the heading, you don’t.

Keep Design a stack that supports getMin() in O(1) time and O(1) extra space small. Meera should finish undo typing in a few lines, not a 40-line dump.

Design a stack that supports getMin() in O(1) time and O(1) extra space exists so Meera can keep undo typing correct in a tiny editor.

Meera ships Design a stack that supports getMin() in O(1) time and O(1) extra space in a tiny editor. That is the use case worth saying.

Design a stack that supports getMin() in O(1) time and O(1) extra space trap: pop on empty. Meera loses marks for that every viva.

After Design a stack that supports getMin() in O(1) time and O(1) extra space, Meera should still remember pop on empty.

One breath for Design a stack that supports getMin() in O(1) time and O(1) extra space, then undo typing, then pop on empty. Sit down.

Diagram

    | 3 |  ← top (pop)
    | 2 |
    | 1 |
    LIFO

Exam tip

For Design a stack that supports getMin() in O(1) time and O(1) extra space: definition + a tiny editor + one failure.

Example

stack = []
stack.append(10)   # push
stack.append(20)
print(stack.pop()) # 20
print(stack[-1])   # peek → 10

Design a stack that supports getMin() in O(1) time and O(1) extra space — stack is LIFO: push/pop from the same end.

Short notes

DefDesign a stack that supports getMin() in O(1) time and O(1) extra space — Meera uses it for undo typing in a tiny editor.
RuleDesign a stack that supports getMin() in O(1) time and O(1) extra space → push / pop LIFO.
RememberDesign a stack that supports getMin() in O(1) time and O(1) extra space + time vs memory (a tiny editor).
UseDesign a stack that supports getMin() in O(1) time and O(1) extra space in a tiny editor (undo typing).
TrapDesign a stack that supports getMin() in O(1) time and O(1) extra space — pop on empty.
ExDesign a stack that supports getMin() in O(1) time and O(1) extra space → undo typing.

DSA · Theory

Design a stack that supports getMin() in O(1) time and O(1) extra space

← All stacks

Theory

725/810

Design a stack that supports getMin() in O(1) time and O(1) extra space

If you can teach Design a stack that supports getMin() in O(1) time and O(1) extra space using undo typing, you know it. If you only know the heading, you don’t.

Keep Design a stack that supports getMin() in O(1) time and O(1) extra space small. Meera should finish undo typing in a few lines, not a 40-line dump.

Design a stack that supports getMin() in O(1) time and O(1) extra space exists so Meera can keep undo typing correct in a tiny editor.

Meera ships Design a stack that supports getMin() in O(1) time and O(1) extra space in a tiny editor. That is the use case worth saying.

Design a stack that supports getMin() in O(1) time and O(1) extra space trap: pop on empty. Meera loses marks for that every viva.

After Design a stack that supports getMin() in O(1) time and O(1) extra space, Meera should still remember pop on empty.

One breath for Design a stack that supports getMin() in O(1) time and O(1) extra space, then undo typing, then pop on empty. Sit down.

Diagram

    | 3 |  ← top (pop)
    | 2 |
    | 1 |
    LIFO

Exam tip

For Design a stack that supports getMin() in O(1) time and O(1) extra space: definition + a tiny editor + one failure.

Example

stack = []
stack.append(10)   # push
stack.append(20)
print(stack.pop()) # 20
print(stack[-1])   # peek → 10

Design a stack that supports getMin() in O(1) time and O(1) extra space — stack is LIFO: push/pop from the same end.

Short notes

DefDesign a stack that supports getMin() in O(1) time and O(1) extra space — Meera uses it for undo typing in a tiny editor.
RuleDesign a stack that supports getMin() in O(1) time and O(1) extra space → push / pop LIFO.
RememberDesign a stack that supports getMin() in O(1) time and O(1) extra space + time vs memory (a tiny editor).
UseDesign a stack that supports getMin() in O(1) time and O(1) extra space in a tiny editor (undo typing).
TrapDesign a stack that supports getMin() in O(1) time and O(1) extra space — pop on empty.
ExDesign a stack that supports getMin() in O(1) time and O(1) extra space → undo typing.

Design a stack that supports getMin() in O(1) time and O(1) extra space

Example

Short notes

Questions

Design a stack that supports getMin() in O(1) time and O(1) extra space

Example

Short notes

Questions