HDU 6149 Valley Numer II（状压DP）

#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b)	for (int i(a); i <= (b); ++i)
#define dec(i, a, b)	for (int i(a); i >= (b); --i)
#define MP		make_pair
#define fi		first
#define se		second


typedef long long LL;

const int N = 53;

int dp[2][(1 << 15) + 20];
int a[N], f[N], mp[N][N];
int n, m, q;
int T, x, y, S, now, ret;

int main(){

	scanf("%d", &T);
	while (T--){
		scanf("%d%d%d", &n, &m, &q);
		memset(dp, 0, sizeof dp);
		memset(mp, 0, sizeof mp);
		memset(f, 0, sizeof f);

		rep(i, 1, m){
			scanf("%d%d", &x, &y);
			mp[x][y] = mp[y][x] = 1;
		}

		rep(i, 0, q - 1){
			scanf("%d", a + i);
			f[a[i]] = 1;
		}

		S = (1 << q) - 1;
		now = 0;
		rep(i, 1, n){
			if (f[i]) continue;
			now ^= 1;
			rep(j, 0, S) dp[now][j] = dp[now ^ 1][j];
			rep(j, 0, S){
				rep(k, 0, q - 1){
					if (!(j & (1 << k)) && mp[i][a[k]]){
						rep(l, k + 1, q - 1){
							if (!(j & (1 << l)) && mp[i][a[l]]){
								int st = j | (1 << k) | (1 << l);
							       	dp[now][st] = max(dp[now][st], dp[now ^ 1][j] + 1);
							}
						}
					}
				}
			}
		}
		
		ret = 0;
		rep(i, 0, S) ret = max(ret, dp[now][i]);
		printf("%d\n", ret);
	}

	return 0;
}