POJ2506 Tiling（递推+大数）

Tiling

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 9420 Accepted: 4482

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

大数问题就是建一个二维数组，存每一位上的数，按递推规律算

#include <iostream>#include<cstdio>#include<cstring>#include<cstdlib>using namespace std;int p[251][1000];//第几个数有多少位void cal(){    int i,j,t=0;    p[0][0]=1;    p[1][0]=1;    for(i=2;i<251;i++)    {        for(j=0;j<1000;j++)        {            t+=p[i-1][j]+2*p[i-2][j];            p[i][j]=t%10;            t=t/10;        }    }}int main(){    int n,i,j;    cal();    while(~scanf("%d",&n))    {        for(i=999;i>=0;i--)            if(p[n][i]!=0)            break;        for(;i>=0;i--)            printf("%d",p[n][i]);        printf("\n");    }    return 0;}