紫书 城市里的间谍 UVa1025

#include<iostream>
#include<string>
#include<cassert>
#include<algorithm>
#include<map>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<vector>
#include<set>
#include<sstream>
#include<fstream>
#include<cstdio>
#include<queue>
#include<unordered_map>
#include<tuple>
#include<complex>
#include<memory>
using namespace std;
const int maxT = 200 + 10;
const int maxN = 50 + 5;
const int maxC = 250 + 10;
const int INF = (1 << 30) - 1;
int dp[maxT][maxN];
int d[maxC], e[maxC];
int t[maxN];
int has_train[maxT][maxN][2];
int main()
{
	//freopen("input.txt", "r", stdin);
	int N;
	int T;
	int kase = 0;
	while (scanf("%d", &N) && N)
	{
		memset(has_train, 0, sizeof(has_train));
		int M1, M2;
		scanf("%d", &T);
		for (int i = 1; i < N; ++i)
		{
			scanf("%d", &t[i]);
		}
		scanf("%d", &M1);
		for (int i = 0; i < M1; ++i)
		{
			scanf("%d", &d[i]);
		}
		scanf("%d", &M2);
		for (int i = 0; i < M2; ++i)
		{
			scanf("%d", &e[i]);
		}
		for (int i = 0; i < M1; ++i)
		{
			int time = d[i];
			for (int j = 1; j <= N && time < maxT; ++j)
			{
				has_train[time][j][0] = 1;
				time += t[j];
			}
		}
		for (int i = 0; i < M2; ++i)
		{
			int time = e[i];
			for (int j = N; j >= 1 && time < maxT; --j)
			{
				has_train[time][j][1] = 1;
				time += t[j - 1];
			}
		}
		for (int i = 1; i <= N - 1; ++i)dp[T][i] = INF;
		dp[T][N] = 0;
		for (int i = T - 1; i >= 0; --i)
		{
			for (int j = 1; j <= N; ++j)
			{
				dp[i][j] = dp[i + 1][j] + 1;
				if (j < N && has_train[i][j][0] && i + t[j] <= T)
					dp[i][j] = min(dp[i][j], dp[i + t[j]][j + 1]);
				if (j > 1 && has_train[i][j][1] && i + t[j - 1] <= T)
					dp[i][j] = min(dp[i][j], dp[i + t[j - 1]][j - 1]);
			}
		}
		cout << "Case Number " << ++kase << ": ";
		if (dp[0][1] >= INF)cout << "impossible\n";
		else
			cout << dp[0][1] << "\n";
	}
}