Tiling

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 8128		Accepted: 3941

Description

In how many ways can you tile a 2xn rectangle by 2x1 or 2x2 tiles? 

Here is a sample tiling of a 2x17 rectangle. 

Input

Input is a sequence of lines, each line containing an integer number 0 <= n <= 250.

Output

For each line of input, output one integer number in a separate line giving the number of possible tilings of a 2xn rectangle. 

Sample Input

2812100200

Sample Output

317127318451004001521529343311354702511071292029505993517027974728227441735014801995855195223534251

Source

公式a[n]=a[n-1]+a[n-2]*2

ac代码

#include
     
      #include
      
       int str[255][100];void fun(){	str[0][0]=1;	str[1][0]=1;	str[2][0]=3;	int temp,i,j;	temp=0;	for(i=3;i<=250;i++)	{		for(j=0;j<100;j++)		{			temp+=(str[i-2][j])*2+str[i-1][j];			str[i][j]=temp%10;			temp/=10;		}	}}int main(){	fun();	int n;	while(scanf("%d",&n)!=EOF)	{		int i;		for(i=99;i>=0;i--)		{			if(str[n][i]!=0)				break;		}		for(;i>=0;i--)		{			printf("%d",str[n][i]);		}		printf("\n");	}	}