제출 #127216

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
127216		Utaha	Sparklers (JOI17_sparklers)	C++14	30 / 100	3 ms	420 KiB

sparklers

/*input
3 2 50
0
200
300
*/
#include <bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ld,ld> pdd;
#define IOS ios_base::sync_with_stdio(0); cin.tie(0)
#define ALL(a) a.begin(),a.end()
#define SZ(a) ((int)a.size())
#define F first
#define S second
#define REP(i,n) for(int i=0;i<((int)n);i++)
#define pb emplace_back
#define MP(a,b) make_pair(a,b)
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define GET_POS(c,x) (lower_bound(c.begin(),c.end(),x)-c.begin())
template<typename T1,typename T2>
ostream& operator<<(ostream& out,pair<T1,T2> P){
	out<<'('<<P.F<<','<<P.S<<')';
	return out;
}

//}}}
const ll maxn=1005;
const ll maxlg=__lg(maxn)+2;
const ll INF64=8000000000000000000LL;
const int INF=0x3f3f3f3f;
const ll MOD=ll(1e9+7);
const ld PI=acos(-1);
const ld eps=1e-9;
//const ll p=880301;
//const ll P=31;

ll mypow(ll a,ll b){
	ll res=1LL;
	while(b){
		if(b&1) res=res*a%MOD;
		a=a*a%MOD;
		
		b>>=1;
	}
	return res;
}

int n,k;
ll t;
ll a[maxn];

vector<ll> A,B;
vector<pll> C,D;

int main(){
	IOS;
	cin>>n>>k>>t;
	k--;
	REP(i,n) cin>>a[i];

	ll l=-1,r=1000000000LL;

	while(l!=r-1){
		ll mid=(l+r)/2;
		// cout<<mid<<'\n';

		A.clear();
		B.clear();
		for(int i=k-1;i>=0;i--){
			A.pb(a[i+1]-a[i]-mid*t*2);
		}
		for(int i=k;i<n-1;i++){
			B.pb(a[i+1]-a[i]-mid*t*2);
		}
		C.clear();D.clear();
		{
			ll pos=0,neg=0;
			for(int i=0;i<SZ(A);i++){
				if(i&&A[i]>=0&&A[i-1]<0){
					C.pb(pos,neg);
					pos=0,neg=0;
				}
				if(A[i]>=0) pos+=A[i];
				else neg-=A[i];
			}
			C.pb(pos,neg);
		}
		{
			ll pos=0,neg=0;
			for(int i=0;i<SZ(B);i++){
				if(i&&B[i]>=0&&B[i-1]<0){
					D.pb(pos,neg);
					pos=0,neg=0;
				}
				if(B[i]>=0) pos+=B[i];
				else neg-=B[i];
			}
			D.pb(pos,neg);
		}
		// for(auto i:C) cout<<i<<' ';
		// cout<<'\n';
		// for(auto i:D) cout<<i<<' ';
		// cout<<'\n';

		ll pt=0;
		int i=0,j=0;
		bool f=1;

		while(i<SZ(C)||j<SZ(D)){
			if(i==SZ(C)){
				pt+=D[j].F;
				if(pt>0){
					f=0;
					break;
				}
				pt-=D[j].S;
				j++;
			}
			else if(j==SZ(D)){
				pt+=C[i].F;
				if(pt>0){
					f=0;
					break;
				}
				pt-=C[i].S;
				i++;
			}
			else if(pt+C[i].F>0){
				pt+=D[j].F;
				if(pt>0){
					f=0;
					break;
				}
				pt-=D[j].S;
				j++;
			}
			else if(pt+D[j].F>0){
				pt+=C[i].F;
				if(pt>0){
					f=0;
					break;
				}
				pt-=C[i].S;
				i++;
			}
			else{
				if(C[i].F<=C[i].S){
					pt+=C[i].F-C[i].S;
					i++;
				}
				else if(D[j].F<=D[j].S){
					pt+=D[j].F-D[j].S;
					j++;
				}
				else{
					if(C[i].S>D[j].S){
						pt+=C[i].F-C[i].S;
						i++;
					}
					else{
						pt+=D[j].F-D[j].S;
						j++;
					}
				}
			}
		}

		if(f) r=mid;
		else l=mid;
	}
	cout<<r<<'\n';
	return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 0 / 20
• Subtask 3: 0 / 50