Submission #434630

#	Time	Username	Problem	Language	Result	Execution time	Memory
434630		frodakcin	Comparing Plants (IOI20_plants)	C++11	14 / 100	4046 ms	8996 KiB

plants

#include "plants.h"
#include <queue>
#include <bitset>

template<typename T> bool ckmin(T& a, const T& b) {return b<a?a=b,1:0;}
template<typename T> bool ckmax(T& a, const T& b) {return b>a?a=b,1:0;}

const int MN = 2e5+10;
const int INF = 0x3f3f3f3f;

int N, K, ctr, ord[MN];
bool v[MN];

//Minmax Segtree
struct minmax
{
	public:
		int min, max;
		minmax(int _mn=INF, int _mx=-INF): min(_mn), max(_mx) {}
		minmax& operator += (const int& o) {min += o, max += o; return *this;}
		minmax& operator -= (const int& o) {min -= o, max -= o; return *this;}
		minmax& operator += (const minmax& o) {ckmin(min, o.min); ckmax(max, o.max); return *this;}

		friend minmax operator + (minmax a, const int& b) {return a+=b;}
		friend minmax operator - (minmax a, const int& b) {return a-=b;}
		friend minmax operator + (minmax a, const minmax& b) {return a+=b;}

		bool contains(int x) {return min <= x && x <= max;}
} range[MN];
minmax mv[1 << 19];
minmax mqry(int n, int l, int r, int ql, int qr)
{
	if(ql <= l && r <= qr) return mv[n];
	else
	{
		int m=l+(r-l)/2; minmax f;
		if(ql < m) f += mqry(n<<1, l, m, ql, qr);
		if(m < qr) f += mqry(n<<1|1, m, r, ql, qr);
		return r;
	}
}
void mupd(int n, int l, int r, int q, minmax val)
{
	if(r-l>1)
	{
		int m=l+(r-l)/2;
		if(q < m) mupd(n<<1, l, m, q, val);
		else mupd(n<<1|1, m, r, q, val);
		mv[n]=mv[n<<1]+mv[n<<1|1];
	}
	else
		mv[n]=val;
}

void init(int k, std::vector<int> r) {
	K=k, N=r.size();
	
	std::queue<int> q;
	int zc=0;
	for(int i=N-K;i<N;++i)
		zc += !r[i];
	for(int i=0;i<N;++i)
	{
		zc -= !r[(N-K+i)%N];
		if(zc==0 && r[i]==0)
			q.push(i);
		zc += !r[i];
	}

	for(;!q.empty();)
	{
		int n=q.front(); q.pop();
		if(r[n] < 0) continue;
		
		// check
		bool ok=1;
		for(int i=1;i<K;++i)
			if(r[(n-i+N)%N]==0)
				ok=0;
		if(!ok) continue;

		// add
		r[n]=-1;
		for(int i=K-1;i>0;--i)
			--r[(n-i+N)%N];
		for(int i=1;i<K;++i)
			if(r[(n+i)%N] == 0)
			{
				q.push((n+i)%N);
				break;
			}
		for(int i=K-1;i>0;--i)
			if(r[(n-i+N)%N] == 0)
			{
				q.push((n-i+N)%N);
				break;
			}

		//modify ans
		ord[n]=ctr++;
		range[n] = minmax(n-K+1, n+K-1);
		range[n] += mqry(1, 0, N, n-K+1, n+K);
		if(n+K>N) range[n] += mqry(1, 0, N, 0, n+K-N)+N;
		if(n-K+1<0) range[n] += mqry(1, 0, N, n-K+1+N, N)-N;
		mupd(1, 0, N, n, range[n]);
		//printf("%d: %d <-> %d\n", n, range[n].min, range[n].max);
	}
	return;
}

bool cover(int a, int b)
{
	if(ord[a]>ord[b]) return 0;
	return range[a].contains(b) || range[a].contains(b+N) || range[a].contains(b-N);
}

int compare_plants(int x, int y)
{
	if(cover(x, y)) return 1;
	if(cover(y, x)) return -1;
	return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 14 / 14
• Subtask 3: 0 / 13
• Subtask 4: 0 / 17
• Subtask 5: 0 / 11
• Subtask 6: 0 / 15
• Subtask 7: 0 / 25