Submission #162189

#	Time	Username	Problem	Language	Result	Execution time	Memory
162189		kostia244	Split the sequence (APIO14_sequence)	C++14	71 / 100	2078 ms	55488 KiB

sequence

#pragma comment(linker, "/stack:200000000")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#include<bits/extc++.h>

/** Begin fast allocation */
const int MAX_MEM = 1e8;
int mpos = 0;
char mem[MAX_MEM];
inline void * operator new ( size_t n ) {
  char *res = mem + mpos;
  mpos += n;
  assert(mpos <= MAX_MEM);
  return (void *)res;
}
inline void operator delete ( void * ) { }
/** End fast allocation */

inline void * operator new [] ( size_t ) { assert(0); }
inline void operator delete [] ( void * ) { assert(0); }
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pb push_back
using namespace std;
using namespace __gnu_pbds;
using ll = long long;
using vi = vector<ll>;
using vvi = vector<vector<ll>>;
const ll mod = 998244353;
using oset = tree<pair<int, int>, null_type, less<pair<int, int>>, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
using vec = pair<ll, ll>;
using ld = long double;
ll dot(vec a, vec b) {
	return a.first*b.first + a.second*b.second;
}
struct cht {
	vector<vec> hull;
	vector<int> id;
	void clear() {
		hull.clear();
		id.clear();
	}
	bool nok(ll x, ll y, ll x1, ll y1, ll x2, ll y2) {
		if(x1==x2)return y1<=y2;
		if(x==x1)return y1<=y2;
		ll a = (y1 - y)/(x1 - x);
		ll b = (y2 - y1)/(x2 - x1);
		if(a<b)return true;
		if(a>b)return false;
		return (y1 - y)*(x2 - x1) - (y2 - y1)*(x1 - x) < (1e-3);
	}
	bool rem() {
		int n = hull.size();
		if (n < 3)
			return 0;
		return nok(hull[n - 3].first, hull[n - 3].second, hull[n - 2].first,
				hull[n - 2].second, hull[n - 1].first, hull[n - 1].second);
	}
	void add(vec x, int i) {
		hull.pb(x);
		id.pb(i);
		while (rem()) {
			swap(hull.back(), hull[hull.size() - 2]), hull.pop_back();
			swap(id.back(), id[id.size() - 2]), id.pop_back();
		}
	}
	ll get(vec x, int &v) {
		ll l = 0, r = (int)hull.size() - 1, a;
		while (r - l > 6) {
			a = l + (r - l) / 2;
			if (dot(x, hull[a]) < dot(x, hull[a+1]))
				l = a;
			else
				r = a+1;
		}
		ll ans = 0;
		while (l <= r) {
			ll t = dot(x, hull[l]);
			if(ans < t)
				v = id[l], ans = t;
			l++;
		}
		return ans;
	}
};

const int MK = 220, MN = 1e5 + 3;
ll n, a[MN], pref[MN], dp[2][MN];
int p[MK][MN];
vi z;
void bt(int a, int b) {
	if(!b)return;
	z.pb(b);
	if (a > 1)
		bt(a - 1, p[a][b]);
}
int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	ll k;
	cin >> n >> k;
	for (int i = 1; i <= n; i++) {
		cin >> a[i], pref[i] = pref[i - 1] + a[i];
	}
	ll ans = -1, g = n - 1;
	cht x;
	for (int at = 1; at <= k; at++) {
		int a = at&1;
		x.clear();
//		if(a==1)
		x.add(vec(0, 0), 0);
		for (int i = 1; i < n; i++) {
			if(i>=at) {
			dp[a][i] = x.get(vec(1, pref[n]-pref[i]), p[at][i]) + pref[i]*(pref[n]-pref[i]);
			ans = max(ans, dp[a][i]);
			if (ans == dp[a][i])
				g = i;
			}else dp[a][i] = dp[a^1][i];
			x.add(vec(dp[a^1][i], -pref[i]), i);
		}
	}

	cout << ans << '\n';
	bt(k, g);
	set<int> xx;
	for(auto i : z)
		cout << i << " ", xx.insert(i);
	int v = 1;
	while(z.size() < k) {
		while(xx.count(v)){v++;}
		xx.insert(v);
		z.pb(v);
		cout << v << " ";
	}
}

Compilation message (stderr)

sequence.cpp:1:0: warning: ignoring #pragma comment  [-Wunknown-pragmas]
 #pragma comment(linker, "/stack:200000000")
 
sequence.cpp: In function 'int main()':
sequence.cpp:132:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(z.size() < k) {
        ~~~~~~~~~^~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 0 / 29