#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
typedef double ll;
typedef long double ld;
typedef complex<ld> cd;
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define F0R(i, a) for (int i = 0; i < (a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define sz(x) (int)x.size()
#define beg(x) x.begin()
#define en(x) x.end()
#define all(x) beg(x), en(x)
#define resz resize
const int MOD = 1000000007; // 998244353
const ll INF = 1e18;
const int MX = 100001;
const ld PI = 4*atan((ld)1);
template<class T> void ckmin(T &a, T b) { a = min(a, b); }
template<class T> void ckmax(T &a, T b) { a = max(a, b); }
template<class A, class B> A operator+=(A& l, const B& r) { return l = l+r; }
template<class A, class B> A operator-=(A& l, const B& r) { return l = l-r; }
template<class A, class B> A operator*=(A& l, const B& r) { return l = l*r; }
template<class A, class B> A operator/=(A& l, const B& r) { return l = l/r; }
namespace input {
template<class T> void re(complex<T>& x);
template<class T1, class T2> void re(pair<T1,T2>& p);
template<class T> void re(vector<T>& a);
template<class T, size_t SZ> void re(array<T,SZ>& a);
template<class T> void re(T& x) { cin >> x; }
void re(double& x) { string t; re(t); x = stod(t); }
void re(ld& x) { string t; re(t); x = stold(t); }
template<class Arg, class... Args> void re(Arg& first, Args&... rest) {
re(first); re(rest...);
}
template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}
using namespace input;
namespace output {
template<class T1, class T2> void pr(const pair<T1,T2>& x);
template<class T, size_t SZ> void pr(const array<T,SZ>& x);
template<class T> void pr(const vector<T>& x);
template<class T> void pr(const set<T>& x);
template<class T1, class T2> void pr(const map<T1,T2>& x);
template<class T> void pr(const T& x) { cout << x; }
template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) {
pr(first); pr(rest...);
}
template<class T1, class T2> void pr(const pair<T1,T2>& x) {
pr("{",x.f,", ",x.s,"}");
}
template<class T> void prContain(const T& x) {
pr("{");
bool fst = 1; trav(a,x) pr(!fst?", ":"",a), fst = 0;
pr("}");
}
template<class T, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
template<class T> void pr(const vector<T>& x) { prContain(x); }
template<class T> void pr(const set<T>& x) { prContain(x); }
template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
void ps() { pr("\n"); }
template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) {
pr(first," "); ps(rest...); // print w/ spaces
}
}
using namespace output;
namespace io {
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void setIO(string s = "") {
ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}
}
using namespace io;
bool Q;
struct Line {
mutable ll k, m, p; // slope, y-intercept, last optimal x
int num;
bool operator<(const Line& o) const {
return Q ? p < o.p : k < o.k;
}
};
struct LineContainer : multiset<Line> {
const ll inf = LLONG_MAX;
ll div(ll a, ll b) { // floored division
if (b < 0) a *= -1, b *= -1;
if (a >= 0) return a/b;
return -((-a+b-1)/b);
}
// updates x->p, determines if y is unneeded
bool isect(iterator x, iterator y) {
if (y == end()) { x->p = inf; return 0; }
if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
else x->p = div(y->m - x->m, x->k - y->k);
return x->p >= y->p;
}
void add(ll k, ll m, int num) {
auto z = insert({k, m, 0,num}), y = z++, x = y;
while (isect(y, z)) z = erase(z);
if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
while ((y = x) != begin() && (--x)->p >= y->p) isect(x, erase(y));
}
pair<ll,int> query(ll x) {
assert(!empty());
Q = 1; auto l = *lb({0,0,x}); Q = 0;
return {l.k * x + l.m, l.num};
}
};
int N,K;
pair<ll,int> solve(double c) {
LineContainer L;
pair<ll,int> ans[MX];
F0R(i,N+1) {
if (i == 0) ans[i] = {0,0};
else {
ans[i] = L.query(i);
ans[i].s ++;
}
if (i < N) L.add(1.0/(N-i),ans[i].f-(double)i/(N-i)-c,ans[i].s);
// (j-i)/(N-i)
}
/*F0R(i,N+1) ps(i,ans[i]);
ps();*/
return ans[N];
}
int main() {
setIO(); re(N,K);
double lo = 0, hi = 2;
F0R(i,40) {
double mid = (lo+hi)/2;
if (solve(mid).s >= K) lo = mid;
else hi = mid;
}
auto t = solve(lo);
cout << fixed << setprecision(10) << t.f+lo*K;
// if >= go higher
// if <= go lower
// ps(solve(0),solve(0.2),solve(0.4),solve(0.6),solve(0.8));
}
/* stuff you should look for
* int overflow, array bounds
* special cases (n=1?), set tle
* do smth instead of nothing and stay organized
*/
Compilation message
akvizna.cpp: In function 'void io::setIn(std::__cxx11::string)':
akvizna.cpp:117:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
~~~~~~~^~~~~~~~~~~~~~~~~~~~~
akvizna.cpp: In function 'void io::setOut(std::__cxx11::string)':
akvizna.cpp:118:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
1920 KB |
Output is correct |
2 |
Correct |
8 ms |
1920 KB |
Output is correct |
3 |
Correct |
7 ms |
1920 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
1920 KB |
Output is correct |
2 |
Correct |
7 ms |
1920 KB |
Output is correct |
3 |
Correct |
8 ms |
1920 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
1920 KB |
Output is correct |
2 |
Correct |
7 ms |
1920 KB |
Output is correct |
3 |
Correct |
7 ms |
1920 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
1920 KB |
Output is correct |
2 |
Correct |
8 ms |
1920 KB |
Output is correct |
3 |
Correct |
6 ms |
1920 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
30 ms |
2176 KB |
Output is correct |
2 |
Correct |
25 ms |
2176 KB |
Output is correct |
3 |
Correct |
22 ms |
2048 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
24 ms |
2176 KB |
Output is correct |
2 |
Correct |
32 ms |
2176 KB |
Output is correct |
3 |
Correct |
22 ms |
2048 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
23 ms |
2048 KB |
Output is correct |
2 |
Correct |
23 ms |
2176 KB |
Output is correct |
3 |
Correct |
22 ms |
2176 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
24 ms |
2048 KB |
Output is correct |
2 |
Correct |
24 ms |
2176 KB |
Output is correct |
3 |
Correct |
26 ms |
2176 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
26 ms |
2176 KB |
Output is correct |
2 |
Correct |
26 ms |
2204 KB |
Output is correct |
3 |
Correct |
22 ms |
2048 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
27 ms |
2168 KB |
Output is correct |
2 |
Correct |
25 ms |
2176 KB |
Output is correct |
3 |
Correct |
24 ms |
2304 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
26 ms |
2168 KB |
Output is correct |
2 |
Correct |
31 ms |
2176 KB |
Output is correct |
3 |
Correct |
22 ms |
2092 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
24 ms |
2140 KB |
Output is correct |
2 |
Correct |
24 ms |
2176 KB |
Output is correct |
3 |
Correct |
27 ms |
2176 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
22 ms |
2048 KB |
Output is correct |
2 |
Correct |
28 ms |
2176 KB |
Output is correct |
3 |
Correct |
25 ms |
2152 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1112 ms |
9312 KB |
Output is correct |
2 |
Correct |
1153 ms |
9628 KB |
Output is correct |
3 |
Correct |
1074 ms |
9168 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1115 ms |
9332 KB |
Output is correct |
2 |
Correct |
1069 ms |
9596 KB |
Output is correct |
3 |
Correct |
1129 ms |
9656 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1110 ms |
9312 KB |
Output is correct |
2 |
Correct |
1181 ms |
9808 KB |
Output is correct |
3 |
Correct |
1220 ms |
9768 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1110 ms |
9516 KB |
Output is correct |
2 |
Correct |
1147 ms |
9608 KB |
Output is correct |
3 |
Correct |
1115 ms |
9444 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1091 ms |
9524 KB |
Output is correct |
2 |
Correct |
1181 ms |
9916 KB |
Output is correct |
3 |
Correct |
1075 ms |
9312 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1186 ms |
9876 KB |
Output is correct |
2 |
Correct |
1152 ms |
9508 KB |
Output is correct |
3 |
Correct |
1072 ms |
9484 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1184 ms |
9544 KB |
Output is correct |
2 |
Correct |
1112 ms |
9208 KB |
Output is correct |
3 |
Correct |
1183 ms |
9224 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1151 ms |
9256 KB |
Output is correct |
2 |
Correct |
1212 ms |
9800 KB |
Output is correct |
3 |
Correct |
1098 ms |
9304 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1162 ms |
9756 KB |
Output is correct |
2 |
Correct |
1097 ms |
9744 KB |
Output is correct |
3 |
Correct |
1307 ms |
9972 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1252 ms |
9740 KB |
Output is correct |
2 |
Correct |
1065 ms |
9440 KB |
Output is correct |
3 |
Correct |
1230 ms |
9848 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1228 ms |
9856 KB |
Output is correct |
2 |
Correct |
1161 ms |
9840 KB |
Output is correct |
3 |
Correct |
1231 ms |
9844 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1179 ms |
9972 KB |
Output is correct |
2 |
Correct |
1272 ms |
9876 KB |
Output is correct |
3 |
Correct |
1342 ms |
9848 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1266 ms |
9800 KB |
Output is correct |
2 |
Correct |
1248 ms |
9900 KB |
Output is correct |
3 |
Correct |
1197 ms |
9720 KB |
Output is correct |