Problem
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
Input: 2
Output: 2
Explanation: There are two ways to climb to the top.
1. 1 step + 1 step
2. 2 steps
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
Code
static int var = [](){
std::ios::sync_with_stdio(false);
cin.tie(NULL);
return 0;
}();
class Solution {
public:
int climbStairs(int n) {
if(n==0)
return 1;
else if(n==1)
return 1;
int left = 1;
int right = 1;
int temp = 0;
for(int i = 2;i <= n;i++){
temp = left + right;
right = left;
left = temp;
}
return temp;
}
};
Result
70. Climbing Stairs.png
