Lesson 1 of 8
Steps written, steps taken
Show on a big screenA search sheet lists the steps of a search, one per line. This one has 5 lines. Does every search take 5 steps?
Step 1 of 4
- The sheet: 5 lines, every time.
- Card 104: found at look 1.
- Card 218: found at look 12.
- Same sheet. Different looks.
No. The sheet has 5 lines every time. A search can take 1 look or 12 looks.
The rule
A look compares a card with the one you want. One look at a card is one comparison. The number of looks a search makes is its steps taken.
The lines you write stay the same. The looks a search takes change with the card.
Searching one by one
A plain search checks the cards one by one. It starts at the first card.
| Where the card is | Looks |
|---|---|
| Place 1 | 1 |
| Place 6 | 6 |
| Place 12 | 12 |
| Not in the row (plain search) | 12 |
A plain search ignores the order. It cannot say "missing" until it has looked at every card. Any card it has not seen could be the one.
Tap a card. Count the looks.
Loading lab…
Try the lab to finish this lesson.