Description:
You are climbing a stair case. It takes n steps to reach to the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
Note: Given n will be a positive integer.
Example 1:
Input: 2
Output: 2
Explanation: There are two ways to climb to the top.
1. 1 step + 1 step
2. 2 steps
Example 2:
Input: 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
My code:
/**
* @param {number} n
* @return {number}
*/
var climbStairs = function(n) {
let num1 = 1, num2 = 2, temp = 0;
if(n == 1 || n == 2) {
return n;
}
for(let i = 3; i <= n; i++) {
temp = num1 + num2;
num1 = num2;
num2 = temp;
}
return temp;
};
Note: 简单算一下前几个结果可以看出是斐波那契数列
