UVA 10051 Tower of Cubes

http://uva.onlinejudge.org/external/100/10051.pdf

DIS变形，多了方向和路径。

#include<algorithm>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<cmath>
using namespace std;
const int maxn = 505;
int a[maxn][6], f[maxn][6], p[maxn][6][2], b[maxn][2];
int n, i, j, k1, k2, w1, w2, sum;
char s[6][10] = { "front", "left", "top", "bottom", "right", "back" };

int main()
{
	int tot = 0, ff = 0;
	while (cin >> n)
	{
		if (n == 0) break; else if (ff) printf("\n"); else ff = 1;
		w1 = 0;	w2 = 0;	memset(p, 0, sizeof(p)); memset(f, 0, sizeof(f));
		for (i = 1; i <= n; i++) cin >> a[i][0] >> a[i][5] >> a[i][1] >> a[i][4] >> a[i][2] >> a[i][3];
		for (i = 1; i <= n; i++)
			for (j = 0; j < 6; j++) f[i][j] = 1;
		for (i = 2; i <= n;i++)
			for (k1 = 0; k1 < 6; k1++)
				for (j = 1; j < i; j++)
					for (k2 = 5; k2 >= 0; k2--)
						if (a[i][k1] == a[j][k2])
						{
							if (f[i][k1] < f[j][5 - k2] + 1)
							{
								f[i][k1] = f[j][5 - k2] + 1;
								p[i][k1][0] = j;
								p[i][k1][1] = 5 - k2;
							}
							if (f[w1][w2] < f[i][k1]) { w1 = i; w2 = k1; }
						}
		printf("Case #%d\n%d\n", ++tot, f[w1][w2]);
		sum = 0;
		while (w1)
		{
			b[sum][0] = w1; b[sum++][1] = w2;
			int u1 = p[w1][w2][0], u2 = p[w1][w2][1];
			w1 = u1; w2 = u2;
		}
		for (i = sum - 1; i >= 0; i--) printf("%d %s\n", b[i][0], s[b[i][1]]);
	}
}