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QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #98954 | #5105. Hand of the Free Marked | uphargaur | Compile Error | / | / | C++20 | 1.4kb | 2023-04-21 02:03:53 | 2023-04-21 02:03:56 |
Judging History
你现在查看的是最新测评结果
- [2023-08-10 23:21:45]
- System Update: QOJ starts to keep a history of the judgings of all the submissions.
- [2023-04-21 02:03:56]
- 评测
- 测评结果：Compile Error
- 用时：0ms
- 内存：0kb
- [2023-04-21 02:03:53]
- 提交
answer
#include <iostream>
using namespace std;
int k, m, n, a[99], b[99];
long double ans, totnum, num, p;
long double nCr(int x, int y) {
long double res = 1;
for (int i = 1; i <= y; ++i)
res /= i;
for (int i = 1; i <= y; ++i)
res *= (x - i + 1);
return res;
}
// long double fact(long double n);
// long double nCr(long double n, long double r)
// {
// return fact(n) / (fact(r) * fact(n - r));
// }
// // Returns factorial of n
// long double fact(long double n)
// {
// if(n==0)
// return 1;
// long double res = 1;
// for (long double i = 2; i <= n; i++)
// res = res * i;
// return res;
// }
void dfs(int nw, int sm) {
if (nw > m) {
if (sm ^ k)
return;
num = 1;
p = 0;
for (int i = 1; i <= m; ++i)
num *= C(a[i], b[i]), p += (long double)b[i] / (a[i] - b[i] + 1);
for (int i = 1; i < k; ++i)
p *= i;
if (p > 1)
ans += num / totnum;
else
ans += num / totnum * p;
return;
}
for (int i = 0; i + sm <= k && i <= a[nw]; ++i)
b[nw] = i, dfs(nw + 1, sm + i);
}
int main() {
cin >> k >> m;
for (int i = 1; i <= m; ++i)
cin >> a[i], n += a[i];
totnum = nCr(n, k);
dfs(1, 0);
cout.precision(10);
cout << fixed << ans << endl;
return 0;
}
Details
answer.code: In function ‘void dfs(int, int)’:
answer.code:39:20: error: ‘C’ was not declared in this scope
39 | num *= C(a[i], b[i]), p += (long double)b[i] / (a[i] - b[i] + 1);
| ^