-
Notifications
You must be signed in to change notification settings - Fork 0
/
climbingStairs.js
60 lines (45 loc) · 1.24 KB
/
climbingStairs.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
// LeetCode #70. Climbing Stairs
/* Instructions
* You are climbing a staircase. It takes n steps to reach the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
Example 1:
Input: n = 2
Output: 2
Explanation: There are two ways to climb to the top.
1. 1 step + 1 step
2. 2 steps
Example 2:
Input: n = 3
Output: 3
Explanation: There are three ways to climb to the top.
1. 1 step + 1 step + 1 step
2. 1 step + 2 steps
3. 2 steps + 1 step
Constraints:
1 <= n <= 45
*/
// Solution
const climbStairs = n => {
let first = 0
let second = 1
let temp;
let i = 0;
while (i < n) {
temp = first + second
first = second
second = temp
i++
}
return second
}
// Explanation
// Declare a variable, first, set equal to 0
// Declare a variable, second, set equal to 1
// Declare an empty number variable, temp
// Declare our loop counter, i, set equal to 0
// Use a while loop to loop through every iteration where i < n
// For each iteration, set temp equal to first + second
// Then, set first equal to second
// Then, set second equal to temp
// Increment i by 1
// At the end of the loop, second will be the number of different ways to climb the stairs