Submission #590164

#	Time	Username	Problem	Language	Result	Execution time	Memory
590164		rainboy	Uplifting Excursion (BOI22_vault)	C11	0 / 100	1 ms	340 KiB

vault

#include <stdio.h>
#include <string.h>

#define N	100
#define S	(N * N * N)
#define N_	30
#define S_	(N_ * N_)
#define INF	0x3f3f3f3f

long long min(long long a, long long b) { return a < b ? a : b; }
long long max(long long a, long long b) { return a > b ? a : b; }

void upd(int *dp, int s_,int a, int k, int c) {
	static int dq[S * 2 + 1], qu[S * 2 + 1];
	int s, r, head, cnt;

	if (a > 0) {
		for (s = 0; s <= s_; s++)
			dq[s] = dp[s] == -INF ? -INF : dp[s] - s / a;
		for (r = 0; r < a; r++) {
			head = cnt = 0;
			for (s = r; s <= s_; s += a) {
				if (dq[s] != -INF) {
					while (cnt && dq[qu[head + cnt - 1]] < dq[s])
						cnt--;
					qu[head + cnt++] = s;
				}
				dp[s] = cnt == 0 ? -INF : dq[qu[head]] + s / a;
				if (cnt && qu[head] == s - a * k)
					head++, cnt--;
			}
		}
	} else if (a < 0) {
		a = -a;
		for (s = 0; s <= s_; s++)
			dq[s] = dp[s] == -INF ? -INF : dp[s] + s / a;
		for (r = 0; r < a; r++) {
			head = cnt = 0;
			for (s = (s_ - r) / a * a + r; s >= 0; s -= a) {
				if (dq[s] != -INF) {
					while (cnt && dq[qu[head + cnt - 1]] < dq[s])
						cnt--;
					qu[head + cnt++] = s;
				}
				dp[s] = cnt == 0 ? -INF : dq[qu[head]] - s / a;
				if (cnt && qu[head] == s + a * k)
					head++, cnt--;
			}
		}
	} else {
		if (c <= 0)
			return;
		for (s = 0; s <= s_; s++)
			if (dp[s] != -INF)
				dp[s] += k * c;
	}
}

int main() {
	static long long kk[N * 2 + 1];
	static int dp[S * 2 + 1], dq[N][S_ + 1];
	int n, a, s1, s2, subtask2;
	long long s, s_, s0, k0, k, ans;

	scanf("%d%lld", &n, &s_);
	subtask2 = n <= N && 0;
	for (a = -n; a <= n; a++) {
		scanf("%lld", &kk[a + n]);
		if (kk[a + n] > N)
			subtask2 = 0;
	}
	if (subtask2) {
		if (s_ < -S || s_ > S) {
			printf("impossible\n");
			return 0;
		}
		for (s = 0; s <= S * 2; s++)
			dp[s] = -INF;
		dp[S + 0] = 0;
		for (a = -n; a <= n; a++)
			upd(dp, S * 2, a, kk[a + n], 1);
		if (dp[S + s_] == -INF)
			printf("impossible\n");
		else
			printf("%d\n", dp[S + s_]);
	} else if (n <= N_) {
		for (s = 0; s <= S_; s++)
			dp[s] = -INF;
		dp[0] = 0;
		for (a = n; a >= 0; a--) {
			memcpy(dq[a], dp, (S_ + 1) * sizeof *dp);
			upd(dp, S_, a, min(kk[a + n], n), 1);
		}
		for (s = 0; s <= S_; s++)
			dp[s] = -INF;
		dp[0] = 0;
		ans = -INF, s0 = 0, k0 = 0;
		for (a = 0; a <= n; a++) {
			for (s1 = 0; s1 <= S_; s1++)
				if (dp[s1] != -INF)
					for (s2 = 0; s2 <= S_; s2++)
						if (dq[a][s2] != -INF) {
							s = s0 - s1 + s2;
							if (a == 0) {
								if (s == s_)
									ans = max(ans, k0 + dp[s1] + dq[a][s2] + kk[a + n]);
							} else {
								if (s <= s_ && (s_ - s) % a == 0 && (k = (s_ - s) / a) <= kk[a + n])
									ans = max(ans, k0 + dp[s1] + dq[a][s2] + k);
							}
						}
			upd(dp, S_, a, min(kk[a + n], n), -1);
			s0 += kk[a + n] * a, k0 += kk[a + n];
		}
		if (ans == -INF)
			printf("impossible\n");
		else
			printf("%lld\n", ans);
	}
	return 0;
}

Compilation message (stderr)

vault.c: In function 'main':
vault.c:65:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |  scanf("%d%lld", &n, &s_);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~
vault.c:68:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |   scanf("%lld", &kk[a + n]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3-1: 0 / 10
• Subtask 3-2: 0 / 10
• Subtask 4-1: 0 / 10
• Subtask 4-2: 0 / 10
• Subtask 5-1: 0 / 10
• Subtask 5-2: 0 / 10
• Subtask 6-1: 0 / 10
• Subtask 6-2: 0 / 10