Submission #6891

#	Time	Username	Problem	Language	Result	Execution time	Memory
6891		qja0950	Split the sequence (APIO14_sequence)	C++98	100 / 100	688 ms	93500 KiB

sequence

#include <stdio.h>

#define MAXN 101101
#define MAXK 222
typedef long long ll;

int N, K;
int A[MAXN];
int S[MAXN];

void INPUT() {
	scanf("%d %d", &N, &K);
	for(int i=1; i<=N; i++) {
		scanf("%d", &A[i]);
		S[i]=S[i-1]+A[i];
	}
}

long long D[2][MAXN];
int Mom[MAXK][MAXN];
long long Stack[3][MAXN];
int Stackp;
bool MyOperator(ll Linea[], ll Lineb[]) {
	ll Line[3][2];
	for(int i=0; i<3; i++) {
		Line[i][0]=Linea[i];
		Line[i][1]=Lineb[i];
	}
	ll temp1=(ll)(Line[0][1]-Line[1][1])*(ll)(Line[2][0]-Line[1][0]);
	ll temp2=(ll)(Line[1][1]-Line[2][1])*(ll)(Line[1][0]-Line[0][0]);
	return temp1>=temp2;
}
int C;
int P;
void Stack_Push(int k) {
	++Stackp;
	Stack[0][Stackp]=(ll)S[k];
	Stack[1][Stackp]=-(ll)S[k]*(ll)S[k]+D[C%2][k];
	Stack[2][Stackp]=k;
}
void Stack_Pop() {
	if(P==Stackp) P--;
	Stackp--;
}
void Stack_Clear() {
	Stackp=0;
}
void Graph(int k) {
	if(Stackp==0) {
		Stack_Push(k);
//		printf("<<<<<%d %lld %lld>>>>>\n", k, Stack[0][Stackp], Stack[1][Stackp]);
		return;
	}
	if(A[k]==0) return;
	if(Stackp==1) {
		Stack_Push(k);
//		printf("<<<<<%d %lld %lld>>>>>\n", k, Stack[0][Stackp], Stack[1][Stackp]);
		return;
	}

	Stack_Push(k);

//		printf("<<<<<%d %lld %lld>>>>>\n", k, Stack[0][Stackp], Stack[1][Stackp]);
//	printf(".%lld\t %lld\t %lld\n", Stack[0][Stackp-2], Stack[0][Stackp-1], Stack[0][Stackp]);
//	printf(".%lld\t %lld\t %lld\n", Stack[1][Stackp-2], Stack[1][Stackp-1], Stack[1][Stackp]);
	while(MyOperator(Stack[0]+Stackp-2, Stack[1]+Stackp-2)) {
		Stack_Pop();
		Stack_Pop();
		Stack_Push(k);
		if(Stackp<=2) break;
	}
}

ll MAX(ll x, ll y) {
	if(x>y) return x;
	else return y;
}
void Find(int i, int j);
void PROCESS() {
//	Trick();
	for(int i=1; i<=K; i++) {
		for(int j=i+1; j<=N; j++) D[i%2][j]=0;
		C=i-1;
		Stack_Clear();
		P=1;
		for(int j=i+1; j<=N; j++) {

			Graph(j-1);
			while(1) {
				if(P>=Stackp) break;
				ll nowa =Stack[0][P]	, nowb =Stack[1][P];
				ll nexta=Stack[0][P+1]	, nextb=Stack[1][P+1];

				ll nowD=nowa*(ll)S[j]+nowb, nextD=nexta*(ll)S[j]+nextb;
//				printf("<%d (%lld %lld) %lld (%lld %lld) %lld : %d>\n"
//						, k, nowa, nowb, nowD, nexta, nextb, nextD, S[j]);
				if(nowD<=nextD) P++;
				else break;
			}
			if(P>=Stackp) P=Stackp;


			ll Da =Stack[0][P]	, Db =Stack[1][P];
			D[i%2][j]=Da*(ll)S[j]+Db;
			Mom[i][j]=Stack[2][P];

//			printf("%d %d : %lld %lld / %lld (%d %d / %d)\n"
//					, i, j, Da, Db, D[i%2][j], k, Stackp, Stack[2][k]);


/*
			for(int k=i; k<j; k++) {
				ll temp=D[1-i%2][k]-((ll)S[k]*(ll)S[k])+(ll)S[j]*(ll)S[k];
				D[i%2][j]=MAX(D[i%2][j], temp);
				if(D[i%2][j]==temp) Mom[i][j]=k;
			}
			printf("%d %d / %lld %d\n"
					, i, j, D[i%2][j], Mom[i][j]);
*/

		}
	}
	long long Ans=0;
	int p=N;
	Ans=MAX(Ans, D[K%2][N]);
	printf("%lld\n", Ans);
	Find(K, p);
}
void Find(int i, int j) {
	if(i==0) return;
	printf("%d ", Mom[i][j]);
	return Find(i-1, Mom[i][j]);
}
int main() {
	INPUT();
	PROCESS();
}

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 29 / 29