LeetCode Climbing Stairs

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?

The original problem is here.

The original code is here.

My Solution

I solve this problem in C++, as below:

/*
*Climbing Stairs  
*Author: shuaijiang
*Email: zhaoshuaijiang8@gmail.com
*/
#include<iostream>
#include<vector>
#include<stdlib.h>
using namespace std;

class Solution {
public:
    int climbStairs(int n) {            
        vector<int> vec;
        vec.push_back(1);
        vec.push_back(1);
        if(n<=1)
            return vec[n];
        for(int i=2;i<=n;i++){
            int num = vec[i-1] + vec[i-2];
            vec.push_back(num);
        }
        return vec[n];
    }
};
//The code below is used for test
int main()
{
    int n = 44;
    Solution s;
    int result = s.climbStairs(n);
    cout<<"result="<<result<<endl;
    system("pause");
    return 0;
}

Note

To solve the problem, I use a vector to save the result of every step, and the distinct ways of the i(th) step is the sum of the i-1 and i-2 steps.