• Question
• Solution

Question

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?

Solution

Result: Accepted Time: x ms

Here should be some explanations.

class Solution {
    int data[130];
public:
    Solution()
    {
        data[0]=data[1]=1;
        for(int i=2;i<130;i++)
            data[i]= data[i-1]+data[i-2];
    }
    int climbStairs(int n) {
        return data[ n&127];
    }
};

Complexity Analytics

• Time Complexity: $O(1)$
• Space Complexity: $O(1)$