/*
sort by b from small to large
optimal construction can be split into two halves
- on the left, all the things are taken
- on the right, only a's are taken
fix the number of b's, let this be t
f(i,j) = min time to use prefix i with j b's
f(i,j) = min(f(i-1,j) + a[i] / t, f(i-1,j-1) + b[i] / t)
now for the suffixes, we need to pick k-i a's at the end,
we must pick the ones with the least a[j] value. this part
can be done in O(n log^2 n)
overall the time complexity is O(n^3)
*/
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 0
#endif
const int N = 505;
const double INF = 1e18;
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
int n, k;
cin >> n >> k;
static array<double, 2> p[N];
for (int i = 0; i < n; i++) {
double a, b;
cin >> a >> b;
if (b == -1)
b = INF;
p[i] = {b, a};
}
sort(p, p + n);
static double g[N][N];
for (int i = 0; i < n; i++) {
vector<double> t;
for (int j = i; j < n; j++)
t.push_back(p[j][1]);
sort(t.begin(), t.end());
g[i][0] = 0;
for (int j = 1; j <= (int) t.size(); j++)
g[i][j] = g[i][j - 1] + t[j - 1];
}
double ans = g[0][k];
for (int t = 0; t <= k; t++) {
static double f[N];
for (int i = 0; i <= t; i++)
f[i] = INF;
f[0] = 0;
for (int i = 0; i < n; i++) {
for (int j = t; j >= 0; j--)
f[j] = min(f[j] + p[i][1] / (t + 1), j == 0 ? INF : f[j - 1] + p[i][0] / j);
if (k - i - 1 >= 0)
ans = min(ans, f[t] + g[i + 1][k - i - 1] / (t + 1));
}
}
cout << fixed << setprecision(12) << ans << '\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
4 ms |
2260 KB |
Output is correct |
6 |
Correct |
9 ms |
2260 KB |
Output is correct |
7 |
Correct |
28 ms |
2260 KB |
Output is correct |
8 |
Correct |
57 ms |
2260 KB |
Output is correct |
9 |
Correct |
96 ms |
2292 KB |
Output is correct |
10 |
Correct |
48 ms |
2260 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
4 ms |
2260 KB |
Output is correct |
6 |
Correct |
9 ms |
2260 KB |
Output is correct |
7 |
Correct |
28 ms |
2260 KB |
Output is correct |
8 |
Correct |
57 ms |
2260 KB |
Output is correct |
9 |
Correct |
96 ms |
2292 KB |
Output is correct |
10 |
Correct |
48 ms |
2260 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
11 ms |
2316 KB |
Output is correct |
13 |
Correct |
13 ms |
2308 KB |
Output is correct |
14 |
Correct |
13 ms |
2260 KB |
Output is correct |
15 |
Correct |
50 ms |
2296 KB |
Output is correct |
16 |
Correct |
49 ms |
2300 KB |
Output is correct |
17 |
Correct |
51 ms |
2260 KB |
Output is correct |
18 |
Correct |
95 ms |
2296 KB |
Output is correct |
19 |
Correct |
102 ms |
2380 KB |
Output is correct |
20 |
Correct |
103 ms |
2292 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
1 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
332 KB |
Output is correct |
5 |
Correct |
1 ms |
328 KB |
Output is correct |
6 |
Correct |
1 ms |
340 KB |
Output is correct |
7 |
Correct |
1 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
328 KB |
Output is correct |
9 |
Correct |
1 ms |
340 KB |
Output is correct |
10 |
Correct |
1 ms |
328 KB |
Output is correct |
11 |
Correct |
0 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
1 ms |
340 KB |
Output is correct |
14 |
Correct |
0 ms |
332 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
1 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
332 KB |
Output is correct |
5 |
Correct |
1 ms |
328 KB |
Output is correct |
6 |
Correct |
1 ms |
340 KB |
Output is correct |
7 |
Correct |
1 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
328 KB |
Output is correct |
9 |
Correct |
1 ms |
340 KB |
Output is correct |
10 |
Correct |
1 ms |
328 KB |
Output is correct |
11 |
Correct |
0 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
1 ms |
340 KB |
Output is correct |
14 |
Correct |
0 ms |
332 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
324 KB |
Output is correct |
18 |
Correct |
1 ms |
328 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
1 ms |
328 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
340 KB |
Output is correct |
24 |
Correct |
1 ms |
340 KB |
Output is correct |
25 |
Correct |
1 ms |
324 KB |
Output is correct |
26 |
Correct |
1 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
0 ms |
340 KB |
Output is correct |
29 |
Correct |
1 ms |
340 KB |
Output is correct |
30 |
Correct |
1 ms |
340 KB |
Output is correct |
31 |
Correct |
1 ms |
324 KB |
Output is correct |
32 |
Correct |
1 ms |
340 KB |
Output is correct |
33 |
Correct |
0 ms |
324 KB |
Output is correct |
34 |
Correct |
0 ms |
340 KB |
Output is correct |
35 |
Correct |
1 ms |
340 KB |
Output is correct |
36 |
Correct |
1 ms |
328 KB |
Output is correct |
37 |
Correct |
1 ms |
340 KB |
Output is correct |
38 |
Correct |
1 ms |
328 KB |
Output is correct |
39 |
Correct |
1 ms |
340 KB |
Output is correct |
40 |
Correct |
1 ms |
340 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
1 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
332 KB |
Output is correct |
5 |
Correct |
1 ms |
328 KB |
Output is correct |
6 |
Correct |
1 ms |
340 KB |
Output is correct |
7 |
Correct |
1 ms |
340 KB |
Output is correct |
8 |
Correct |
0 ms |
328 KB |
Output is correct |
9 |
Correct |
1 ms |
340 KB |
Output is correct |
10 |
Correct |
1 ms |
328 KB |
Output is correct |
11 |
Correct |
0 ms |
340 KB |
Output is correct |
12 |
Correct |
1 ms |
340 KB |
Output is correct |
13 |
Correct |
1 ms |
340 KB |
Output is correct |
14 |
Correct |
0 ms |
332 KB |
Output is correct |
15 |
Correct |
1 ms |
340 KB |
Output is correct |
16 |
Correct |
1 ms |
340 KB |
Output is correct |
17 |
Correct |
1 ms |
324 KB |
Output is correct |
18 |
Correct |
1 ms |
328 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
1 ms |
328 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
340 KB |
Output is correct |
24 |
Correct |
1 ms |
340 KB |
Output is correct |
25 |
Correct |
1 ms |
324 KB |
Output is correct |
26 |
Correct |
1 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
0 ms |
340 KB |
Output is correct |
29 |
Correct |
1 ms |
340 KB |
Output is correct |
30 |
Correct |
1 ms |
340 KB |
Output is correct |
31 |
Correct |
1 ms |
324 KB |
Output is correct |
32 |
Correct |
1 ms |
340 KB |
Output is correct |
33 |
Correct |
0 ms |
324 KB |
Output is correct |
34 |
Correct |
0 ms |
340 KB |
Output is correct |
35 |
Correct |
1 ms |
340 KB |
Output is correct |
36 |
Correct |
1 ms |
328 KB |
Output is correct |
37 |
Correct |
1 ms |
340 KB |
Output is correct |
38 |
Correct |
1 ms |
328 KB |
Output is correct |
39 |
Correct |
1 ms |
340 KB |
Output is correct |
40 |
Correct |
1 ms |
340 KB |
Output is correct |
41 |
Correct |
1 ms |
724 KB |
Output is correct |
42 |
Correct |
1 ms |
724 KB |
Output is correct |
43 |
Correct |
1 ms |
724 KB |
Output is correct |
44 |
Correct |
1 ms |
724 KB |
Output is correct |
45 |
Correct |
1 ms |
708 KB |
Output is correct |
46 |
Correct |
1 ms |
724 KB |
Output is correct |
47 |
Correct |
1 ms |
724 KB |
Output is correct |
48 |
Correct |
1 ms |
724 KB |
Output is correct |
49 |
Correct |
1 ms |
724 KB |
Output is correct |
50 |
Correct |
2 ms |
716 KB |
Output is correct |
51 |
Correct |
2 ms |
724 KB |
Output is correct |
52 |
Correct |
2 ms |
712 KB |
Output is correct |
53 |
Correct |
2 ms |
724 KB |
Output is correct |
54 |
Correct |
1 ms |
724 KB |
Output is correct |
55 |
Correct |
1 ms |
716 KB |
Output is correct |
56 |
Correct |
1 ms |
724 KB |
Output is correct |
57 |
Correct |
1 ms |
724 KB |
Output is correct |
58 |
Correct |
1 ms |
708 KB |
Output is correct |
59 |
Correct |
1 ms |
724 KB |
Output is correct |
60 |
Correct |
1 ms |
724 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
102 ms |
2312 KB |
Output is correct |
2 |
Correct |
100 ms |
2300 KB |
Output is correct |
3 |
Correct |
105 ms |
2296 KB |
Output is correct |
4 |
Correct |
102 ms |
2296 KB |
Output is correct |
5 |
Correct |
104 ms |
2260 KB |
Output is correct |
6 |
Correct |
108 ms |
2388 KB |
Output is correct |
7 |
Correct |
101 ms |
2260 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
4 ms |
2260 KB |
Output is correct |
6 |
Correct |
9 ms |
2260 KB |
Output is correct |
7 |
Correct |
28 ms |
2260 KB |
Output is correct |
8 |
Correct |
57 ms |
2260 KB |
Output is correct |
9 |
Correct |
96 ms |
2292 KB |
Output is correct |
10 |
Correct |
48 ms |
2260 KB |
Output is correct |
11 |
Correct |
0 ms |
212 KB |
Output is correct |
12 |
Correct |
11 ms |
2316 KB |
Output is correct |
13 |
Correct |
13 ms |
2308 KB |
Output is correct |
14 |
Correct |
13 ms |
2260 KB |
Output is correct |
15 |
Correct |
50 ms |
2296 KB |
Output is correct |
16 |
Correct |
49 ms |
2300 KB |
Output is correct |
17 |
Correct |
51 ms |
2260 KB |
Output is correct |
18 |
Correct |
95 ms |
2296 KB |
Output is correct |
19 |
Correct |
102 ms |
2380 KB |
Output is correct |
20 |
Correct |
103 ms |
2292 KB |
Output is correct |
21 |
Correct |
1 ms |
340 KB |
Output is correct |
22 |
Correct |
1 ms |
340 KB |
Output is correct |
23 |
Correct |
1 ms |
340 KB |
Output is correct |
24 |
Correct |
0 ms |
332 KB |
Output is correct |
25 |
Correct |
1 ms |
328 KB |
Output is correct |
26 |
Correct |
1 ms |
340 KB |
Output is correct |
27 |
Correct |
1 ms |
340 KB |
Output is correct |
28 |
Correct |
0 ms |
328 KB |
Output is correct |
29 |
Correct |
1 ms |
340 KB |
Output is correct |
30 |
Correct |
1 ms |
328 KB |
Output is correct |
31 |
Correct |
0 ms |
340 KB |
Output is correct |
32 |
Correct |
1 ms |
340 KB |
Output is correct |
33 |
Correct |
1 ms |
340 KB |
Output is correct |
34 |
Correct |
0 ms |
332 KB |
Output is correct |
35 |
Correct |
1 ms |
340 KB |
Output is correct |
36 |
Correct |
1 ms |
340 KB |
Output is correct |
37 |
Correct |
1 ms |
324 KB |
Output is correct |
38 |
Correct |
1 ms |
328 KB |
Output is correct |
39 |
Correct |
1 ms |
340 KB |
Output is correct |
40 |
Correct |
1 ms |
328 KB |
Output is correct |
41 |
Correct |
1 ms |
340 KB |
Output is correct |
42 |
Correct |
1 ms |
340 KB |
Output is correct |
43 |
Correct |
1 ms |
340 KB |
Output is correct |
44 |
Correct |
1 ms |
340 KB |
Output is correct |
45 |
Correct |
1 ms |
324 KB |
Output is correct |
46 |
Correct |
1 ms |
340 KB |
Output is correct |
47 |
Correct |
1 ms |
340 KB |
Output is correct |
48 |
Correct |
0 ms |
340 KB |
Output is correct |
49 |
Correct |
1 ms |
340 KB |
Output is correct |
50 |
Correct |
1 ms |
340 KB |
Output is correct |
51 |
Correct |
1 ms |
324 KB |
Output is correct |
52 |
Correct |
1 ms |
340 KB |
Output is correct |
53 |
Correct |
0 ms |
324 KB |
Output is correct |
54 |
Correct |
0 ms |
340 KB |
Output is correct |
55 |
Correct |
1 ms |
340 KB |
Output is correct |
56 |
Correct |
1 ms |
328 KB |
Output is correct |
57 |
Correct |
1 ms |
340 KB |
Output is correct |
58 |
Correct |
1 ms |
328 KB |
Output is correct |
59 |
Correct |
1 ms |
340 KB |
Output is correct |
60 |
Correct |
1 ms |
340 KB |
Output is correct |
61 |
Correct |
1 ms |
724 KB |
Output is correct |
62 |
Correct |
1 ms |
724 KB |
Output is correct |
63 |
Correct |
1 ms |
724 KB |
Output is correct |
64 |
Correct |
1 ms |
724 KB |
Output is correct |
65 |
Correct |
1 ms |
708 KB |
Output is correct |
66 |
Correct |
1 ms |
724 KB |
Output is correct |
67 |
Correct |
1 ms |
724 KB |
Output is correct |
68 |
Correct |
1 ms |
724 KB |
Output is correct |
69 |
Correct |
1 ms |
724 KB |
Output is correct |
70 |
Correct |
2 ms |
716 KB |
Output is correct |
71 |
Correct |
2 ms |
724 KB |
Output is correct |
72 |
Correct |
2 ms |
712 KB |
Output is correct |
73 |
Correct |
2 ms |
724 KB |
Output is correct |
74 |
Correct |
1 ms |
724 KB |
Output is correct |
75 |
Correct |
1 ms |
716 KB |
Output is correct |
76 |
Correct |
1 ms |
724 KB |
Output is correct |
77 |
Correct |
1 ms |
724 KB |
Output is correct |
78 |
Correct |
1 ms |
708 KB |
Output is correct |
79 |
Correct |
1 ms |
724 KB |
Output is correct |
80 |
Correct |
1 ms |
724 KB |
Output is correct |
81 |
Correct |
102 ms |
2312 KB |
Output is correct |
82 |
Correct |
100 ms |
2300 KB |
Output is correct |
83 |
Correct |
105 ms |
2296 KB |
Output is correct |
84 |
Correct |
102 ms |
2296 KB |
Output is correct |
85 |
Correct |
104 ms |
2260 KB |
Output is correct |
86 |
Correct |
108 ms |
2388 KB |
Output is correct |
87 |
Correct |
101 ms |
2260 KB |
Output is correct |
88 |
Correct |
9 ms |
2252 KB |
Output is correct |
89 |
Correct |
8 ms |
2260 KB |
Output is correct |
90 |
Correct |
14 ms |
2320 KB |
Output is correct |
91 |
Correct |
17 ms |
2324 KB |
Output is correct |
92 |
Correct |
32 ms |
2260 KB |
Output is correct |
93 |
Correct |
31 ms |
2260 KB |
Output is correct |
94 |
Correct |
65 ms |
2304 KB |
Output is correct |
95 |
Correct |
62 ms |
2240 KB |
Output is correct |
96 |
Correct |
83 ms |
2260 KB |
Output is correct |
97 |
Correct |
85 ms |
2300 KB |
Output is correct |
98 |
Correct |
53 ms |
2296 KB |
Output is correct |
99 |
Correct |
55 ms |
2248 KB |
Output is correct |
100 |
Correct |
56 ms |
2304 KB |
Output is correct |
101 |
Correct |
62 ms |
2296 KB |
Output is correct |
102 |
Correct |
56 ms |
2300 KB |
Output is correct |
103 |
Correct |
53 ms |
2300 KB |
Output is correct |
104 |
Correct |
54 ms |
2260 KB |
Output is correct |
105 |
Correct |
49 ms |
2296 KB |
Output is correct |