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]]);
}
}