Submission #253691

#	Time	Username	Problem	Language	Result	Execution time	Memory
253691		Red_Inside	K blocks (IZhO14_blocks)	C++17	0 / 100	1095 ms	2204 KiB

blocks

#include <bits/stdc++.h>
#include <random>

//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")

#define ll long long
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define o cout<<"BUG"<<endl;
#define	IOS ios_base::sync_with_stdio(0);
#define en "\n"
#define FOR(i, j, n) for(int j = i; j < n; ++j)
#define forn(i, j, n) for(int j = i; j <= n; ++j)
#define nfor(i, j, n) for(int j = n; j >= i; --j)
#define sortv(vv) sort(vv.begin(), vv.end())
#define all(v) v.begin(), v.end()
#define ld long double
#define ull unsigned long long

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
using namespace std;
const ll maxn=1e5+100, inf=1e18,LOG=18,mod=1e9+7;
ll block = 300, timer = 0;
const ld EPS = 1e-7;

#define bt(i) (1 << (i))
#define int ll
#define y1 yy
#define pii pair <int, int>

int n, k, a[maxn], step[maxn];
pii dp[maxn];
int parse[maxn][LOG];

int calc(int l, int r)
{
	int len = r - l + 1;
	//7 8 9 10 11
	return max(parse[l][step[len]], parse[r - (1 << step[len]) + 1][step[len]]);
}

stack <pair <int, pair <int, pii> > > st;
multiset <pii> sett;

int check(int pen, int ty)
{
	while(st.size()) st.pop();
	sett.clear();
	dp[0] = {0, 0};
	forn(1, i, n)
	{
		dp[i] = {inf, inf};
		//dp[i] = min(dp[i - 1], dp[j - 1] + calc(j, i) - pen (1 <= j <= i));
		auto upd = mp(a[i], mp(i, dp[i - 1]));
		while(st.size() && st.top().f <= a[i])
		{
			auto was = st.top();
			sett.erase(sett.find({was.s.s.f + was.f, was.s.s.s}));
			st.pop();
			upd.s.f = was.s.f;
			upd.s.s = min(upd.s.s, was.s.s);
		}
		st.push(upd);
		sett.insert({upd.f + upd.s.s.f, upd.s.s.s});
		pii temp = *sett.begin();
		if(dp[i] > mp(temp.f - pen, temp.s + 1))
		{
			dp[i] = {temp.f - pen, temp.s + 1};
		}
//		cout << dp[i].f << " " << dp[i].s << endl;
	}
	if(ty == 1)
		return dp[n].s;
	else
		return dp[n].f + dp[n].s * pen;
}

main()
{
	IOS
	cin >> n >> k;
	step[1] = 0;
	forn(2, i, n)
	{
		step[i] = step[i - 1];
		if((1 << (step[i] + 1)) <= i)
		{
			step[i]++;
		}
	}
	forn(1, i, n)
	{
		cin >> a[i];
		parse[i][0] = a[i];
	}
	forn(1, j, LOG - 1)
	{
		forn(1, i, n)
		{
			if(i + (1 << (j - 1)) <= n)
				parse[i][j] = max(parse[i][j - 1], parse[i + (1 << (j - 1))][j - 1]);
			else
				parse[i][j] = parse[i][j - 1];
		}
	}
//	cout << check(2, 1);
//	exit(0);
	int l = 0;
	int r = inf;
	while(r - l > 1)
	{
		int mid = (l + r) / 2;
		if(check(mid, 1) > k)
		{
			r = mid;
		}
		else
		{
			l = mid;
		}
	}
	int rb = r - 1;
	l = 0;
	r = inf;
	while(r - l > 1)
	{
		int mid = (l + r) / 2;
		if(check(mid, 1) >= k)
		{
			r = mid;
		}
		else
		{
			l = mid;
		}
	}
	int lb = r;
//	cout << lb << " " << rb << endl;
//	cout << check(2, 1) << endl;
	int ans = inf;
	forn(lb, i, rb)
	{
		ans = min(ans, check(i, 2));
	}
	cout << ans;
}

Compilation message (stderr)

blocks.cpp:82:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^

• Subtask 1: 0 / 14
• Subtask 2: 0 / 18
• Subtask 3: 0 / 21
• Subtask 4: 0 / 47