제출 #855241

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
855241		willychan	Chorus (JOI23_chorus)	C++14	0 / 100	0 ms	348 KiB

chorus

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
//#include<bits/extc++.h>
//__gnu_pbds
const int N = 5005;
pair<ll,int> dp[N];
int Bpa[N];
int n,K;
bool ok(ll v){
	for(int i=0;i<=n;i++) dp[i] = {1e18,0};
	dp[0]={0,0};
	for(int i=1;i<=n;i++){
		ll cost = 0;
		for(int j=1;j<=i;j++){
			cost+=max(0,i-Bpa[i-j+1]);	
			dp[i] = min({dp[i-j].first+cost+v,dp[i-j].second+1},dp[i]);
		}
	}
	//cout<<(dp[n].second<=K)<<" "<<dp[n].first<<" "<<v<<"\n";
	return (dp[n].second<=K);
}
 
int main(){
	ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	cin>>n>>K;			
	string s;cin>>s;
	int pa = 0;
	int pb = 0;
	for(int i=1;i<=2*n;i++){
		if(s[i-1]=='A') pa++;
		if(s[i-1]=='B') Bpa[++pb]=pa;
	}
	ll l = -1;ll r = 1e15;
	while(r-l>1){
		ll mid = l+((r-l)/2);
	//	cout<<l<<" "<<mid<<" "<<r<<"t1\n";
		if(ok(mid)) r = mid;
		else l = mid;
	//	cout<<l<<" "<<mid<<" "<<r<<"t2\n";
	}
	ok(r);
	cout<<dp[n].first-r*dp[n].second<<"\n";

	return 0;
}

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• Subtask 2: 0 / 24
• Subtask 3: 0 / 21
• Subtask 4: 0 / 26
• Subtask 5: 0 / 13