Submission #282600

#	Time	Username	Problem	Language	Result	Execution time	Memory
282600		cgiosy	새로운 문제 (COCI19_akvizna)	C++17	130 / 130	1348 ms	2596 KiB

Main

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
using flt=double;

int main() {
	ios::sync_with_stdio(0);cin.tie(0);
	int N, K;
	cin>>N>>K;
	flt l=0, r=2;
	vector<int> C(N+1), P(N+1);
	cout<<fixed<<setprecision(9);
	auto f=[&](flt m) {
		vector<double> D(N+1);
		vector<int> T(1<<32-__builtin_clz(N));
		auto f=[&](int j, int i) {
			return D[j]+flt(i-j)/i;
		};
		auto cmp=[&](int i, int j, int x) {
			return f(i, x)>f(j, x);
		};
		auto add=[&](int a) {
			int s=1, e=N, i=1;
			while(i) {
				int m=s+e>>1, &b=T[i];
				if(cmp(a, b, m)) swap(a, b);
				if(cmp(a, b, s)) e=m-1, i=i*2;
				else if(cmp(a, b, e)) s=m+1, i=i*2+1;
				else break;
			}
		};
		auto get=[&](int x) {
			int s=1, e=N, i=1, a=0;
			while(i) {
				int m=s+e>>1, b=T[i];
				if(cmp(b, a, x)) a=b;
				if(x<m) e=m-1, i=i*2;
				else if(x>m) s=m+1, i=i*2+1;
				else break;
			}
			return a;
		};
		D[0]=0;
		for(int i=1; i<=N; i++) {
			add(i-1);
			int p=get(i);
			P[i]=p;
			C[i]=C[p]+1;
			D[i]=f(p, i)-m;
		}
		return make_pair(C[N], D[N]+K*m);
	};
	while(r-l>1e-12) {
		flt m=(l+r)/2;
		auto[k,x]=f(m);
		if(k<K) r=m;
		else if(k>K) l=m;
		else { l=r=m; break; }
	}
	cout<<fixed<<setprecision(9)<<f((l+r)/2).second;
}

Compilation message (stderr)

akvizna.cpp: In lambda function:
akvizna.cpp:15:22: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   15 |   vector<int> T(1<<32-__builtin_clz(N));
      |                    ~~^~~~~~~~~~~~~~~~~
akvizna.cpp: In lambda function:
akvizna.cpp:25:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   25 |     int m=s+e>>1, &b=T[i];
      |           ~^~
akvizna.cpp: In lambda function:
akvizna.cpp:35:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   35 |     int m=s+e>>1, b=T[i];
      |           ~^~

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