QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#488967#8815. Space StationZ_drjWA 70ms9336kbC++201.3kb2024-07-24 16:46:402024-07-24 16:46:40

Judging History

你现在查看的是最新测评结果

  • [2024-07-30 16:51:06]
  • hack成功,自动添加数据
  • (/hack/760)
  • [2024-07-24 16:46:40]
  • 评测
  • 测评结果:WA
  • 用时:70ms
  • 内存:9336kb
  • [2024-07-24 16:46:40]
  • 提交

answer

#include <cstdio>
#include <algorithm>

using i64 = long long;

const int N = 105;
const int mod = 998244353;

int n, m;
int a[N], mx;

i64 qpow(i64 a, i64 b = mod - 2) {
	i64 ans = 1;
	for (; b; b >>= 1, a = a * a % mod) {
		if (b & 1) {
			ans = ans * a % mod;
		}
	}
	return ans;
}

i64 fac[N], inv[N];
void prework() {
	fac[0] = inv[0] = inv[1] = 1;
	for (int i = 1; i <= n; i++) {
		fac[i] = fac[i - 1] * i % mod;
	}

	for (int i = 2; i <= n; i++) {
		inv[i] = (mod - mod / i) * inv[mod % i] % mod;
	}
	
	for (int i = 1; i <= n; i++) {
		inv[i] = inv[i] * inv[i - 1] % mod;
	}
}

i64 invC(int x, int y) {
	return inv[x] * fac[y - 1] % mod * fac[x - y] % mod;
}

i64 f[N][N * N * 2];

int main() {
	scanf("%d %d", &n, &m);

	for (int i = 1; i <= n; i++) {
		scanf("%d", a + i);
		mx += a[i];
	}

	prework();

	f[0][0] = 1;
	for (int i = 1; i <= n; i++) {
		for (int j = n; j >= 1; j--) {
			for (int k = a[i]; k <= mx; k++) {
				f[j][k] = (f[j][k] + f[j - 1][k - a[i]]);
				f[j][k] >= mod? f[j][k] -= mod: 0;
			}
		}
	}

	i64 ans = 0;	
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= mx; j++) {
			ans = (ans + invC(n, i) * f[i][j] * std::min(j, i * m)) % mod;
		}
	}

	printf("%lld", ans);
	return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 1656kb

input:

3 3
2 3 4

output:

499122185

result:

ok 1 number(s): "499122185"

Test #2:

score: 0
Accepted
time: 0ms
memory: 1640kb

input:

5 1
10 20 30 40 50

output:

5

result:

ok 1 number(s): "5"

Test #3:

score: 0
Accepted
time: 0ms
memory: 1644kb

input:

1 9
37

output:

9

result:

ok 1 number(s): "9"

Test #4:

score: 0
Accepted
time: 0ms
memory: 1660kb

input:

5 5
24 41 29 6 40

output:

25

result:

ok 1 number(s): "25"

Test #5:

score: 0
Accepted
time: 0ms
memory: 1676kb

input:

10 34
91 86 1 14 98 13 85 64 91 20

output:

707882334

result:

ok 1 number(s): "707882334"

Test #6:

score: -100
Wrong Answer
time: 70ms
memory: 9336kb

input:

100 9
83 99 170 80 174 137 1 91 111 35 69 39 148 76 142 90 105 30 114 176 196 85 26 109 162 167 171 148 169 162 159 3 4 6 33 61 163 7 77 63 8 20 13 51 26 11 149 136 134 187 96 95 113 104 128 48 167 74 18 91 200 62 167 32 5 180 189 39 63 111 68 72 81 128 42 13 57 180 111 91 83 177 34 45 158 29 114 33...

output:

812387028

result:

wrong answer 1st numbers differ - expected: '82380556', found: '812387028'