Submission #41945

#	Time	Username	Problem	Language	Result	Execution time	Memory
41945		cmaster	Split the sequence (APIO14_sequence)	C++14	100 / 100	686 ms	85880 KiB

sequence

#include <bits/stdc++.h>
/*#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>*/
 
#define pb push_back
#define mp make_pair
#define sz(s) ((int)(s.size()))
#define all(s) s.begin(), s.end()
#define rep(i, a, n) for (int i = a; i <= n; ++i)
#define per(i, n, a) for (int i = n; i >= a; --i)
#define onlycin ios_base::sync_with_stdio(false); cin.tie(0) 
#define F first
#define S second
using namespace std;
// using namespace __gnu_pbds;
typedef long long ll;
typedef unsigned long long ull;
/*typedef tree<
pair < int, int >,
null_type,
less< pair < int, int > >,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;*/
// find_by_order() order_of_key()
const int MAXN = (int)1e5+228;
const char nxtl = '\n';
const int mod = (int)1e9+7;
const double eps = (double)1e-7;
template<typename T> inline bool updmin(T &a, const T &b) {return a > b ? a = b, 1 : 0;}
template<typename T> inline bool updmax(T &a, const T &b) {return a < b ? a = b, 1 : 0;}
#define ld long double
struct line {
	ll slope, delta;
	int id;
	line(ll _slope = 0, ll _delta = 0, int _id = 0) {
		slope = _slope, delta = _delta, id = _id;
	}
	inline ld intersection(const line &X) const {
		return (delta - X.delta - 0.0) / (X.slope - slope - 0.0);
	}
	inline ll get(const ll &x) {
		return slope*x + delta;
	}
};
vector < line > have;
int ptr = 0;
inline void addLine(const line &X) {
	while(sz(have) > 1) {
		ld int1 = have.back().intersection(have[sz(have)-2]);
		if(X.slope == have.back().slope) {
			if(X.delta >= have.back().delta) {
				have.pop_back(); continue;
			}
			assert(0);
			return;
		}
		ld int2 = X.intersection(have.back());
		if(int2 <= int1) have.pop_back();
		else break;
	}
	have.pb(X);
	updmin(ptr, sz(have)-1);
}
inline int Find(ll x) {
	while(ptr+1 < sz(have) && have[ptr].get(x) <= have[ptr+1].get(x)) ptr++;
	return ptr;
}

int n, k, a[MAXN], come[202][MAXN];
ll pref[MAXN], dp[2][MAXN];

int main() {
	#ifdef accepted
		freopen(".in", "r", stdin);
		freopen(".out", "w", stdout);
	#endif
	onlycin;
	cin >> n >> k;
	rep(i, 1, n) cin >> a[i];
	rep(i, 1, n) pref[i] = pref[i-1]+a[i];
	rep(i, 1, n) dp[1][i] = 0;
	memset(come, 255, sizeof come);
	rep(ii, 2, k+1) {
		int i = ii%2;
		rep(j, 1, n) dp[i][j] = -(ll)1e17;
		ptr = 0;
		have.clear();
		addLine(line(pref[ii-1], dp[i^1][ii-1]-pref[ii-1]*pref[ii-1], ii-1));
		rep(j, ii, n) {
			int idd = Find(pref[j]);
			dp[i][j] = have[idd].get(pref[j]);
			come[ii][j] = have[idd].id;
			addLine(line(pref[j], dp[i^1][j]-pref[j]*pref[j], j));
			/* rep(j1, 1, j-1) {
				if(updmax(dp[i][j], dp[i^1][j1] + pref[j]*pref[j1]-pref[j1]*pref[j1])) come[ii][j] = j1;
			}*/
		}
	}
	k++;
	cout << dp[k&1][n] << nxtl;
	vector < int > res;
	int i = n;
	while(come[k][i] > 0) {
		res.pb(come[k][i]);
		i = come[k][i];
		k--;
	}
	sort(all(res));
	for(auto &to : res) cout << to << ' ';
	return 0;
}

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