Climbing Stairs With 1, 2 or 3 Steps
EasyP1Coding
Count the number of distinct ways to climb a staircase of n steps when each hop can be 1, 2 or 3 steps. Different orders count as different ways: 1 + 2 and 2 + 1 are two ways to climb 3 steps.
There is exactly one way to climb 0 steps (do nothing).
Example 1
- Input
- n = 3
- Output
- 4
- Why
- 1+1+1, 1+2, 2+1 and 3.
Example 2
- Input
- n = 4
- Output
- 7
Example 3
- Input
- n = 0
- Output
- 1
Constraints
- 0 <= n <= 30
Hints
Give it a real attempt first. Run shows which examples fail.
Saved automatically
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