mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
21 lines
345 B
C++
21 lines
345 B
C++
|
#include<stdio.h>
|
||
|
|
#include<iostream>
|
||
|
|
#include<cstring>
|
||
|
|
#include<cmath>
|
||
|
|
using namespace std;
|
||
|
|
typedef long long ll;
|
||
|
|
int main()
|
||
|
|
{
|
||
|
|
ll a[51];
|
||
|
|
a[1] = 3;
|
||
|
|
a[2] = 6;
|
||
|
|
a[3] = 6;
|
||
|
|
for(int i=4;i<51;++i){
|
||
|
|
a[i] = a[i-1] + 2*a[i-2];
|
||
|
|
}
|
||
|
|
int n;
|
||
|
|
while(cin >> n && n){
|
||
|
|
cout << a[n] << endl;
|
||
|
|
}
|
||
|
|
}
|