HDU 1143 Tri TILING__DP

Tri Tiling Time limit:2000/1000 MS (java/others) Memory limit:65536/32768 K (java/others)
Total submission (s): 2168 accepted Submission (s): 1240


Problem Description in many ways can, tile a 3xn rectangle with 2x1 dominoes? This is a sample tiling of 3x12 rectangle.



Input input consists of several test cases followed by a line containing-1. Each test case is a line containing an integer 0≤n≤30.

Output for each test case, output one integer number giving the number of possible tilings.

Sample Input

2 8 12-1
Sample Output

3 153 2131
Source University of Waterloo local Contest 2005.09.24 Solution: The 3*n of the floor can be 1*2 by the board seamless splicing of the number of programs, first n of the odd time is certainly unable to splice, when n is even when, the whole as f[i] by the j*3 and F[i-j] two parts, j*3 part is not by the 2*3 splicing of the scheme species number, j= At 2, there are only 3 scenarios, and there are 2 options when j!=2

#include <cstdio>
int main ()
{
    int f[31];
    int i,j;
    int n;


    F[0]=1;
    for (i=1;i<=30;i+=2)    f[i]=0;
    for (i=2;i<=30;i+=2)
    {
        f[i]=0;
        for (j=2;j<=i;j+=2)
        {
            if (j==2)    f[i]+=3*f[i-j];
            else        f[i]+=2*f[i-j];
        }
    Freopen ("In.txt", "R", stdin);
    Freopen ("OUT.txt", "w", stdout);

    while (scanf ("%d", &n), n!=-1)    printf ("%d\n", F[n]);
    return 0;
}