#include <algorithm>
#include <iomanip>
#include <iostream>
#include <utility>
#include <vector>
using namespace std;
#define int long long
using pdd = pair<long double, long double>;
const long double INF = 1e18;
const int maxn = 505;
int n, k;
vector<pdd> vc;
long double dp[maxn][maxn];
long double sf[maxn][maxn]; // sf[i][j] 從 A[i~(n-1)] 選 j 個最小的數字
void build_sf() {
for (int i = 1; i < maxn; i++) {
fill(sf[i] + 1, sf[i] + maxn, INF);
}
for (int i = n - 1; i >= 0; i--) {
vector<long double> cur;
for (int j = i; j < n; j++) {
cur.push_back(vc[j].first);
}
sort(cur.begin(), cur.end());
sf[i][0] = 0;
for (int j = 1; j <= k; j++) {
if (j > (int)(cur.size()))
break;
else
sf[i][j] = sf[i][j - 1] + cur[j - 1];
}
}
}
long double solve(const int t) {
for (int i = 0; i < n; i++) {
fill(dp[i], dp[i] + (t + 1), INF);
}
for (int i = 0; i < n; i++) {
if (i == 0) {
dp[i][0] = vc[i].first / (t + 1.0);
dp[i][1] = vc[i].second;
continue;
}
for (int j = 0; j <= t; j++) {
if (j == 0) {
dp[i][0] = dp[i - 1][0] + vc[i].first / (t + 1.0);
} else {
long double x = dp[i - 1][j] + vc[i].first / (t + 1.0);
long double y = dp[i - 1][j - 1] + vc[i].second * 1.0 / j;
dp[i][j] = min(x, y);
}
}
}
long double res = sf[0][k];
for (int i = t - 1; i < n - k + t; i++) {
res = min(res, dp[i][t] + sf[i + 1][k - t] / (t + 1.0));
}
return res;
}
signed main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cout << fixed << setprecision(15);
cin >> n >> k;
for (int i = 0; i < n; i++) {
int x, y;
cin >> x >> y;
if (y == -1) {
vc.push_back({x, INF});
} else {
vc.push_back({x, y});
}
}
sort(vc.begin(), vc.end(),
[](pdd a, pdd b) { return a.second < b.second; });
build_sf();
long double res = sf[0][k];
for (int t = 1; t <= k; t++) {
res = min(res, solve(t));
}
cout << res << '\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
4308 KB |
Output is correct |
2 |
Correct |
4 ms |
4308 KB |
Output is correct |
3 |
Correct |
4 ms |
4320 KB |
Output is correct |
4 |
Correct |
4 ms |
4308 KB |
Output is correct |
5 |
Correct |
24 ms |
6672 KB |
Output is correct |
6 |
Correct |
81 ms |
7224 KB |
Output is correct |
7 |
Correct |
233 ms |
8256 KB |
Output is correct |
8 |
Correct |
520 ms |
8292 KB |
Output is correct |
9 |
Correct |
882 ms |
8340 KB |
Output is correct |
10 |
Correct |
440 ms |
8300 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
4308 KB |
Output is correct |
2 |
Correct |
4 ms |
4308 KB |
Output is correct |
3 |
Correct |
4 ms |
4320 KB |
Output is correct |
4 |
Correct |
4 ms |
4308 KB |
Output is correct |
5 |
Correct |
24 ms |
6672 KB |
Output is correct |
6 |
Correct |
81 ms |
7224 KB |
Output is correct |
7 |
Correct |
233 ms |
8256 KB |
Output is correct |
8 |
Correct |
520 ms |
8292 KB |
Output is correct |
9 |
Correct |
882 ms |
8340 KB |
Output is correct |
10 |
Correct |
440 ms |
8300 KB |
Output is correct |
11 |
Correct |
3 ms |
4308 KB |
Output is correct |
12 |
Correct |
111 ms |
7388 KB |
Output is correct |
13 |
Correct |
113 ms |
7492 KB |
Output is correct |
14 |
Correct |
94 ms |
7380 KB |
Output is correct |
15 |
Correct |
431 ms |
8292 KB |
Output is correct |
16 |
Correct |
488 ms |
8352 KB |
Output is correct |
17 |
Correct |
455 ms |
8220 KB |
Output is correct |
18 |
Correct |
891 ms |
8380 KB |
Output is correct |
19 |
Correct |
879 ms |
8296 KB |
Output is correct |
20 |
Correct |
938 ms |
8424 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
4308 KB |
Output is correct |
2 |
Correct |
4 ms |
4308 KB |
Output is correct |
3 |
Correct |
3 ms |
4308 KB |
Output is correct |
4 |
Correct |
4 ms |
4308 KB |
Output is correct |
5 |
Correct |
3 ms |
4308 KB |
Output is correct |
6 |
Correct |
4 ms |
4300 KB |
Output is correct |
7 |
Correct |
4 ms |
4228 KB |
Output is correct |
8 |
Correct |
4 ms |
4308 KB |
Output is correct |
9 |
Incorrect |
4 ms |
4308 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
4308 KB |
Output is correct |
2 |
Correct |
4 ms |
4308 KB |
Output is correct |
3 |
Correct |
3 ms |
4308 KB |
Output is correct |
4 |
Correct |
4 ms |
4308 KB |
Output is correct |
5 |
Correct |
3 ms |
4308 KB |
Output is correct |
6 |
Correct |
4 ms |
4300 KB |
Output is correct |
7 |
Correct |
4 ms |
4228 KB |
Output is correct |
8 |
Correct |
4 ms |
4308 KB |
Output is correct |
9 |
Incorrect |
4 ms |
4308 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
4308 KB |
Output is correct |
2 |
Correct |
4 ms |
4308 KB |
Output is correct |
3 |
Correct |
3 ms |
4308 KB |
Output is correct |
4 |
Correct |
4 ms |
4308 KB |
Output is correct |
5 |
Correct |
3 ms |
4308 KB |
Output is correct |
6 |
Correct |
4 ms |
4300 KB |
Output is correct |
7 |
Correct |
4 ms |
4228 KB |
Output is correct |
8 |
Correct |
4 ms |
4308 KB |
Output is correct |
9 |
Incorrect |
4 ms |
4308 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
946 ms |
8288 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
4308 KB |
Output is correct |
2 |
Correct |
4 ms |
4308 KB |
Output is correct |
3 |
Correct |
4 ms |
4320 KB |
Output is correct |
4 |
Correct |
4 ms |
4308 KB |
Output is correct |
5 |
Correct |
24 ms |
6672 KB |
Output is correct |
6 |
Correct |
81 ms |
7224 KB |
Output is correct |
7 |
Correct |
233 ms |
8256 KB |
Output is correct |
8 |
Correct |
520 ms |
8292 KB |
Output is correct |
9 |
Correct |
882 ms |
8340 KB |
Output is correct |
10 |
Correct |
440 ms |
8300 KB |
Output is correct |
11 |
Correct |
3 ms |
4308 KB |
Output is correct |
12 |
Correct |
111 ms |
7388 KB |
Output is correct |
13 |
Correct |
113 ms |
7492 KB |
Output is correct |
14 |
Correct |
94 ms |
7380 KB |
Output is correct |
15 |
Correct |
431 ms |
8292 KB |
Output is correct |
16 |
Correct |
488 ms |
8352 KB |
Output is correct |
17 |
Correct |
455 ms |
8220 KB |
Output is correct |
18 |
Correct |
891 ms |
8380 KB |
Output is correct |
19 |
Correct |
879 ms |
8296 KB |
Output is correct |
20 |
Correct |
938 ms |
8424 KB |
Output is correct |
21 |
Correct |
4 ms |
4308 KB |
Output is correct |
22 |
Correct |
4 ms |
4308 KB |
Output is correct |
23 |
Correct |
3 ms |
4308 KB |
Output is correct |
24 |
Correct |
4 ms |
4308 KB |
Output is correct |
25 |
Correct |
3 ms |
4308 KB |
Output is correct |
26 |
Correct |
4 ms |
4300 KB |
Output is correct |
27 |
Correct |
4 ms |
4228 KB |
Output is correct |
28 |
Correct |
4 ms |
4308 KB |
Output is correct |
29 |
Incorrect |
4 ms |
4308 KB |
Output isn't correct |
30 |
Halted |
0 ms |
0 KB |
- |