题解 | N阶楼梯上楼问题

//第n阶台阶由第n-1阶走一步和第n-2阶走一个2步
#include<iostream>
#include<cstdio>
using namespace std;
const int MAXN =91;
long long int dp[MAXN];
int main(){
    int n;
    scanf("%d",&n);
    dp[0]=1;
    dp[1]=1;
    for(int i=2;i<MAXN;i++){
        dp[i] =dp[i-1]+dp[i-2];
    }
    cout<<dp[n]<<endl;
    return 0;
}