dsaView

Constant

Same speed always — input size is completely irrelevant.

Array[i] · HashMap.get()

Logarithmic

Input doubles → only 1 extra step. The binary search magic.

Binary search · BST lookup

Linear

Touch every element once. Often unavoidable — and that's ok.

Single loop · Array scan

Linearithmic

The ceiling for comparison-based sorting. Small cost, big order.

Merge sort · Heap sort

Quadratic

Two nested loops. Fine for n < 1 000, painful beyond that.

Bubble sort · All pairs

Cubic

Three nested loops. Only viable for very small inputs (n < 200).

Naive matrix multiply

Exponential

Every new element doubles the work. Keep n ≤ 20 or walk away.

All subsets · Recursive Fib

Factorial

Every possible ordering explored. Practical only for n ≤ 10.

All permutations · TSP brute