O(1)
—Constant Time
DreamThe fastest possible — input size simply does not matter.
Mental model
Think of a row of numbered post-office boxes. Box #47 is always at slot 47. You walk straight to it — whether there are 10 boxes or 10 million makes absolutely no difference.
Interactive Visualisation
🏣 Think of a row of numbered post-office boxes. Box #7 is always at slot 7 — no searching needed. Whether there are 10 boxes or 10 million, you go straight to it in one step.
Array size:
0
1
2
3
4
5
6
7
8
9
10
11
How it scales — (spoiler: it doesn't)
81 op
121 op
161 op
241 op
1001 op
1M1 op
How it scales
n = 1
1 op
n = 100
1 op
n = 10,000
1 op
n = 1,000,000
1 op