BestCoder Round #50 (div.2)-----C The mook jong

The mook jong

 Time Limit: 2000/1000 MS (Java/Others)

 

 Memory Limit: 65536/65536 K (Java/Others)

Problem Description

ZJiaQ want to become a strong man, so he decided to play the mook jong。ZJiaQ want to put some mook jongs in his backyard. His backyard consist of n bricks that is 1*1,so it is 1*n。ZJiaQ want to put a mook jong in a brick. because of the hands of the mook jong， the distance of two mook jongs should be equal or more than 2 bricks. Now ZJiaQ want to know how many ways can ZJiaQ put mook jongs legally(at least one mook jong).

Input

There ar multiply cases. For each case, there is a single integer n( 1 < = n < = 60)

Output

Print the ways in a single line for each case.

Sample Input

1	
2
3
4
5
6

Sample Output

1
2
3
5
8
12

分析：找规律题，推导公式。最后得到的公式是ans[i]=ans[i-3]+1+ans[i-1]。

CODE：

#include <iostream>
using namespace std;

int main()
{
    int n;
    long long ans[66]={0,1,2,3};
    for(int i=4;i<66;i++){
        ans[i]=ans[i-3]+1+ans[i-1];
    }
    while(cin>>n){
        cout<<ans[n]<<endl;
    }
    return 0;
}