Submission #590146

#	Time	Username	Problem	Language	Result	Execution time	Memory
590146		rainboy	Uplifting Excursion (BOI22_vault)	C11	20 / 100	3620 ms	17984 KiB

vault

#include <stdio.h>

#define N	100
#define S	1000000
#define INF	0x3f3f3f3f

int max(int a, int b) { return a > b ? a : b; }

void upd(int *dp, 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 * 2; 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 * 2; 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 * 2; s++)
			dq[s] = dp[s] == -INF ? -INF : dp[s] + s / a;
		for (r = 0; r < a; r++) {
			head = cnt = 0;
			for (s = (S * 2 - 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 * 2; s++)
			if (dp[s] != -INF)
				dp[s] += k * c;
	}
}

int main() {
	static long long kk[N * 2 + 1];
	static int dp[S * 2 + 1];
	int n, a, s;
	long long s_;

	scanf("%d%lld", &n, &s_);
	for (a = -n; a <= n; a++)
		scanf("%lld", &kk[a + n]);
	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, a, kk[a + n], 1);
	if (dp[S + s_] == -INF)
		printf("impossible\n");
	else
		printf("%d\n", dp[S + s_]);
	return 0;
}

Compilation message (stderr)

vault.c: In function 'main':
vault.c:61:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |  scanf("%d%lld", &n, &s_);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~
vault.c:63:3: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |   scanf("%lld", &kk[a + n]);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 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