oj.uz

답안 #1037746

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1037746 2024-07-29T07:36:59 Z ㅇㅇ(223.39)(#11011) Chorus (JOI23_chorus) C++17
0 / 100
 1 ms 2396 KB 
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,popcnt,abm,mmx,avx,avx2,fma")
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
using ll=long long;
using db=double;
using pll=array<ll,2>;
using tll=array<ll,3>;
const ll inf=1e18;
const int N=1000005;
int n,k,a[N],m,f[N];
string s;
ll S[N];
pll dp[N];
ll base,ans;
struct ConvexHullTrick{
	tll L[N];
	int sz,p;
	db cross(tll a,tll b){
		return (db)(b[1]-a[1])/(a[0]-b[0]);
	}
	void add_line(tll l){
		while(sz>=2&&cross(L[sz-1],L[sz])>=cross(L[sz],l)) sz--;
		p=min(p,sz);
		p=max(p,1);
		L[++sz]=l;
	}
	pll qry(ll x){
		if(!sz) return {-1,-1};
		while(p<sz&&cross(L[p],L[p+1])<=x) p++;
		return {L[p][0]*x+L[p][1],L[p][2]};
	}
}CHT;
pll Do(ll C){
	dp[0]={0,0};
	deque<int> dq;
	dq.push_back(0);
	CHT.sz=0; CHT.p=1;
	for(int i=1;i<=n;i++){
		dp[i]={inf,inf};
		while(dq.size()&&dq.front()<=f[i]-2) dq.pop_front();
		if(dq.size()) dp[i]={dp[dq.front()][0]+C,dp[dq.front()][1]+1};
		for(int j=max(0,f[i-1]-1);j<=f[i]-2;j++) CHT.add_line({-j,dp[j][0]-(ll)j*(j+1)/2+S[j]+C,dp[j][1]+1});
		pll Q=CHT.qry(i);
		if(Q[1]!=-1) dp[i]=min(dp[i],{Q[0]+(ll)(f[i]-1)*i+(ll)(i-1)*i/2-S[f[i]-1],Q[1]});
		while(dq.size()&&dp[dq.back()]>=dp[i]) dq.pop_back();
		dq.push_back(i);
	}
	return dp[n];
}
int main(){
	ios::sync_with_stdio(false); cin.tie(0);
	cin>>n>>k>>s;
	for(int i=1;i<=2*n;i++) if(s[i-1]=='B') a[++m]=i;
	for(int i=1;i<=n;i++) if(a[i]<2*i){
		base+=2*i-a[i];
		a[i]=2*i;
	}
	for(int i=1;i<=n;i++) S[i]=S[i-1]+a[i];
	f[1]=1;
	for(int i=2;i<=n;i++){
		f[i]=f[i-1];
		while(i+f[i]-a[f[i]]>0) f[i]++;
	}
	ll L=-1e10,R=1e10;
	while(L<=R){
		ll M=(L+R)>>1;
		auto [dp,cnt]=Do(M);
		ans=max(ans,dp-k*M);
		if(cnt<=k) R=M-1;
		else L=M+1;
	}
	cout<<base+ans;
	return 0;
}

Subtask #1
0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 2396 KB Output is correct
4 Correct 0 ms 2396 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 0 ms 2396 KB Output is correct
7 Correct 0 ms 2396 KB Output is correct
8 Incorrect 0 ms 2396 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 2396 KB Output is correct
4 Correct 0 ms 2396 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 0 ms 2396 KB Output is correct
7 Correct 0 ms 2396 KB Output is correct
8 Incorrect 0 ms 2396 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 2396 KB Output is correct
4 Correct 0 ms 2396 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 0 ms 2396 KB Output is correct
7 Correct 0 ms 2396 KB Output is correct
8 Incorrect 0 ms 2396 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
0 / 26.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 2396 KB Output is correct
4 Correct 0 ms 2396 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 0 ms 2396 KB Output is correct
7 Correct 0 ms 2396 KB Output is correct
8 Incorrect 0 ms 2396 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #5
0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 0 ms 2396 KB Output is correct
4 Correct 0 ms 2396 KB Output is correct
5 Correct 1 ms 2396 KB Output is correct
6 Correct 0 ms 2396 KB Output is correct
7 Correct 0 ms 2396 KB Output is correct
8 Incorrect 0 ms 2396 KB Output isn't correct
9 Halted 0 ms 0 KB -