Submission #15240

#	Time	Username	Problem	Language	Result	Execution time	Memory
15240		myungwoo	달리는 게임 (kriii3_E)	C++14	70 / 70	225 ms	40784 KiB

E

#include <bits/stdc++.h>
using namespace std;

#define MAXN 1000006
typedef long long lld;

const double eps = 1e-7;
int N;
int A[MAXN];
int stk[MAXN], scnt; double cp[MAXN];
lld D[MAXN], Nu[MAXN], S[MAXN];

inline lld get_y0(int i)
{ return D[i] - Nu[i] + S[i] * i; }

inline double cross_point(int a, int b)
{
	lld q1 = get_y0(a), q2 = get_y0(b);
	return (double)(q1 - q2) / (b - a);
}

int main()
{
	scanf("%d", &N);
	for (int i=1;i<=N;i++) scanf("%d", A+i);
	for (int i=1;i<=N;i++) Nu[i] = Nu[i-1] + (lld)i * A[i], S[i] = S[i-1] + A[i];
	lld ans = 0;
	stk[++scnt] = 0; cp[scnt] = -1e17;
	for (int i=1;i<=N;i++){
		int j = stk[upper_bound(cp+1, cp+scnt+1, -S[i] + eps) - cp - 1];
		D[i] = max(D[i-1], get_y0(j) - S[i] * j + Nu[i]);
		ans = max(ans, D[i]);

		while (scnt > 1 && cross_point(stk[scnt-1], i) < cp[scnt] + eps) scnt--;
		stk[++scnt] = i; cp[scnt] = cross_point(stk[scnt-1], i);
	}
	printf("%lld\n", ans);
}

• Subtask 1: 26 / 26
• Subtask 2: 44 / 44