#include "bits/stdc++.h"
using namespace std;
#define int long long
const int MAXN = 3e5 + 10;
const int MOD = 998244353;
#define ll __int128
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
ll read() { int x; cin >> x; return (ll)x; }
long long bm(long long b, long long p) {
if(p==0) return 1 % MOD;
long long r = bm(b, p >> 1);
if(p&1) return (((r*r) % MOD) * b) % MOD;
return (r*r) % MOD;
}
long long inv(long long b) {
return bm(b, MOD-2);
}
long long f[MAXN];
long long nCr(int n, int r) {
long long ans = f[n]; ans *= inv(f[r]); ans %= MOD;
ans *= inv(f[n-r]); ans %= MOD; return ans;
}
long long fib[MAXN], lucas[MAXN];
void precomp() {
for(int i=0; i<MAXN; i++) f[i] = (i == 0 ? 1 % MOD : (f[i-1] * i) % MOD);
lucas[0] = 2;
lucas[1] = 1;
for(int i=2; i<MAXN; i++) lucas[i] = (lucas[i-2] + lucas[i-1]) % MOD;
fib[0] = 0;
fib[1] = 1;
for(int i=2; i<MAXN; i++) fib[i] = (fib[i-2] + fib[i-1]) % MOD;
}
int fastlog(int x) {
return (x == 0 ? -1 : 64 - __builtin_clzll(x) - 1);
}
void google(int i) { cout << "Case #" << i << ": "; }
int csb(int l, int r, int k) { // count number of [l, r] such that i & 2^k > 0
if(l > r) return 0;
if(l == 0) {
int s = r / (1ll << (k+1)); // number of complete cycles
int t = r % (1ll << (k+1));
int ans = s * (1ll << k);
ans += (t >= (1ll << k) ? t - (1ll << k) + 1 : 0);
return ans;
}
else return csb(0, r, k) - csb(0, l - 1, k);
}
int lis(vector<int> a) {
int n = a.size();
int bucket[n+1];
for(int i=1; i<=n; i++) bucket[i] = 1e18;
int ans = 1;
for(int x: a) {
auto it = lower_bound(bucket + 1, bucket +n +1, x);
int d = distance(bucket, it);
ans = max(ans, d);
bucket[d] = min(bucket[d], x);
}
return ans;
}
bool cmp(pair<int, int> x, pair<int, int> y) {
if(x.second == y.second) return x.first < y.first;
return x.second < y.second;
}
void solve(int tc) {
int n, k;
cin >> n >> k;
int a[n+1], b[n+1];
pair<int, int> p[n+1];
for(int i=1; i<=n; i++) {
cin >> p[i].first >> p[i].second;
if(p[i].second == -1) p[i].second = 1226;
}
sort(p+1, p+n+1, cmp);
for(int i=1; i<=n; i++) a[i] = p[i].first, b[i] = p[i].second;
double dp[k+1][n+2][n+1];
for(int i=0; i<=k; i++) for(int j=0; j<n+2; j++) for(int l=0; l<n+1; l++) dp[i][j][l] = 1e18;
dp[0][1][0] = 0;
for(int i=1; i<=k; i++) {
for(int j=1; j<=n+1; j++) {
for(int l=1; l<=n; l++) {
// include l, 'A'
dp[i][j][l] = dp[i-1][j][l-1] + a[l] * 1.0 / j;
// include l, 'B'
if(b[l] != 1226) dp[i][j][l] = min(dp[i][j][l], dp[i-1][j-1][l-1] + b[l] * 1.0 / (j-1));
// don't include l
dp[i][j][l] = min(dp[i][j][l], dp[i][j][l-1]);
}
}
}
double ans = 1e18;
for(int i=1; i<=n+1; i++) ans = min(ans, dp[k][i][n]);
cout << fixed << setprecision(6) << ans << "\n";
}
int32_t main() {
precomp();
ios::sync_with_stdio(0); cin.tie(0);
int t = 1; //cin >> t;
for(int i=1; i<=t; i++) solve(i);
}
// I don't know geometry.
// Teaming is unfair.
/*
7
5
31 33 (2)
19 27 (8)
28 36 (8)
38 51 (13)
20 35 (15)
25 56 (31)
11 57 (46)
7
5
19 27
31 33
20 35
28 36
38 51
25 56
11 57
optimal order:
7
5
19 27
31 33
28 36
38 51
25 56
11 57
20 35
*/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
8 ms |
7252 KB |
Output is correct |
2 |
Correct |
8 ms |
7300 KB |
Output is correct |
3 |
Correct |
7 ms |
7252 KB |
Output is correct |
4 |
Correct |
7 ms |
7372 KB |
Output is correct |
5 |
Correct |
92 ms |
107772 KB |
Output is correct |
6 |
Correct |
228 ms |
255424 KB |
Output is correct |
7 |
Correct |
427 ms |
501580 KB |
Output is correct |
8 |
Correct |
639 ms |
747600 KB |
Output is correct |
9 |
Correct |
859 ms |
993728 KB |
Output is correct |
10 |
Correct |
599 ms |
698384 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
8 ms |
7252 KB |
Output is correct |
2 |
Correct |
8 ms |
7300 KB |
Output is correct |
3 |
Correct |
7 ms |
7252 KB |
Output is correct |
4 |
Correct |
7 ms |
7372 KB |
Output is correct |
5 |
Correct |
92 ms |
107772 KB |
Output is correct |
6 |
Correct |
228 ms |
255424 KB |
Output is correct |
7 |
Correct |
427 ms |
501580 KB |
Output is correct |
8 |
Correct |
639 ms |
747600 KB |
Output is correct |
9 |
Correct |
859 ms |
993728 KB |
Output is correct |
10 |
Correct |
599 ms |
698384 KB |
Output is correct |
11 |
Correct |
7 ms |
7380 KB |
Output is correct |
12 |
Correct |
272 ms |
304644 KB |
Output is correct |
13 |
Correct |
279 ms |
304652 KB |
Output is correct |
14 |
Correct |
275 ms |
304644 KB |
Output is correct |
15 |
Correct |
631 ms |
698492 KB |
Output is correct |
16 |
Correct |
637 ms |
698388 KB |
Output is correct |
17 |
Correct |
600 ms |
698388 KB |
Output is correct |
18 |
Correct |
896 ms |
993604 KB |
Output is correct |
19 |
Correct |
864 ms |
993692 KB |
Output is correct |
20 |
Correct |
870 ms |
993692 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
7 ms |
7252 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
7 ms |
7252 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
7 ms |
7252 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
901 ms |
993752 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
8 ms |
7252 KB |
Output is correct |
2 |
Correct |
8 ms |
7300 KB |
Output is correct |
3 |
Correct |
7 ms |
7252 KB |
Output is correct |
4 |
Correct |
7 ms |
7372 KB |
Output is correct |
5 |
Correct |
92 ms |
107772 KB |
Output is correct |
6 |
Correct |
228 ms |
255424 KB |
Output is correct |
7 |
Correct |
427 ms |
501580 KB |
Output is correct |
8 |
Correct |
639 ms |
747600 KB |
Output is correct |
9 |
Correct |
859 ms |
993728 KB |
Output is correct |
10 |
Correct |
599 ms |
698384 KB |
Output is correct |
11 |
Correct |
7 ms |
7380 KB |
Output is correct |
12 |
Correct |
272 ms |
304644 KB |
Output is correct |
13 |
Correct |
279 ms |
304652 KB |
Output is correct |
14 |
Correct |
275 ms |
304644 KB |
Output is correct |
15 |
Correct |
631 ms |
698492 KB |
Output is correct |
16 |
Correct |
637 ms |
698388 KB |
Output is correct |
17 |
Correct |
600 ms |
698388 KB |
Output is correct |
18 |
Correct |
896 ms |
993604 KB |
Output is correct |
19 |
Correct |
864 ms |
993692 KB |
Output is correct |
20 |
Correct |
870 ms |
993692 KB |
Output is correct |
21 |
Incorrect |
7 ms |
7252 KB |
Output isn't correct |
22 |
Halted |
0 ms |
0 KB |
- |