Submission #304386

#	Time	Username	Problem	Language	Result	Execution time	Memory
304386		myungwoo	Comparing Plants (IOI20_plants)	C++17	100 / 100	1363 ms	43500 KiB

plants

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

#define MAXN 200005
#define debug(...) fprintf(stderr, __VA_ARGS__); fflush(stderr);
typedef pair<int, int> pii;

int N, K, R[MAXN];
int H[MAXN], nxt_r[MAXN][18], nxt_l[MAXN][18];

template <typename T>
struct SegTree{
	int n_bits, TS, ST;
	int range_l(int x){ return ((x<<(__builtin_clz(x)-31+n_bits)) ^ (1<<n_bits)) + 1; }
	int range_r(int x){ return ((x<<(__builtin_clz(x)-31+n_bits) ^ ((1<<(__builtin_clz(x)-31+n_bits))-1)) ^ (1<<n_bits)) + 1; }
	struct Value{
		T value, lazysum;
	};
	vector<Value> tree;
	SegTree(int arr[]){
		n_bits = 32-__builtin_clz(N-1);
		TS = 1 << n_bits+1; ST = TS/2-1;
		tree.resize(TS, {0, 0});
		for (int i=ST+1;i<TS;i++) tree[i].value = i-ST <= N ? arr[i-ST] : 1e9;
		for (int i=ST;i;i--) tree[i].value = min(tree[i*2].value, tree[i*2+1].value);
	}
	void propagate(int n){
		if (n <= ST){
			tree[n*2].value += tree[n].lazysum, tree[n*2+1].value += tree[n].lazysum;
			tree[n*2].lazysum += tree[n].lazysum, tree[n*2+1].lazysum += tree[n].lazysum;
		}
		tree[n].lazysum = 0;
	}
	void update(int n, int l, int r, const int &v){
		int s = range_l(n), e = range_r(n);
		if (l > r || e < l || r < s) return;
		if (l <= s && e <= r){
			tree[n].value += v, tree[n].lazysum += v;
			return;
		}
		propagate(n);
		update(n*2, l, r, v);
		update(n*2+1, l, r, v);
		tree[n].value = min(tree[n*2].value, tree[n*2+1].value);
	}
	int findzero(int n){
		if (tree[n].value != 0) return 0;
		propagate(n);
		if (n > ST) return n-ST;
		if (!tree[n*2].value) return findzero(n*2);
		else if (!tree[n*2+1].value) return findzero(n*2+1);
		else assert(0);
	}
};

struct ZeroContainer{
	set<int> pos, non_covered;
	set<int>::iterator _left(set<int>::iterator it){
		auto ret = it;
		if (ret == pos.begin()) ret = pos.end();
		return --ret;
	}
	set<int>::iterator _right(set<int>::iterator it){
		auto ret = it; ret++;
		if (ret == pos.end()) return pos.begin();
		return ret;
	}
	void insert(int p){
		auto it = pos.insert(p).first;
		auto l = _left(it), r = _right(it);
		if (l == it || (*it-*l+N)%N >= K) non_covered.insert(p);
		if (r != it && (*r-*it+N)%N < K) non_covered.erase(*r);
	}
	void remove(int p){
		auto it = pos.find(p);
		auto l = _left(it), r = _right(it);
		if (l != it && r != it && (l == r || (*r-*l+N)%N >= K)) non_covered.insert(*r);
		pos.erase(it);
	}
	int pop_smallest(){
		int ret = *non_covered.begin(); non_covered.erase(ret);
		remove(ret);
		return ret;
	}
};

int go_left(int n, int d)
{ return (n - d%N - 1 + N)%N + 1; }

int go_right(int n, int d)
{ return (n + d%N - 1 + N)%N + 1; }

void init(int K, vector<int> r)
{
	::K = K;
	N = r.size();
	for (int i=1;i<=N;i++) R[i] = r[i-1];

	{
		SegTree<int> segtree(R);
		ZeroContainer zc;
		for (int ord=N;ord;ord--){
			for (;;){
				int p = segtree.findzero(1);
				if (!p) break;
				zc.insert(p);
				segtree.update(1, p, p, 1e9);
			}
			int x = zc.pop_smallest();
			H[x] = ord;
			segtree.update(1, max(1, x-K+1), x-1, -1);
			if (x-K+1 < 1) segtree.update(1, N-(1-(x-K+1))+1, N, -1);
		}
	}

	{
		set <pii> s;
		for (int i=1;i<=K;i++) s.insert({H[i], i});
		for (int i=1;i<=N;i++){
			auto it = s.lower_bound({H[i], 0});
			if (it != s.begin()){
				it--;
				nxt_r[i][0] = (it->second - i + N) % N;
			}
			int t = (i+K-1)%N+1;
			s.insert({H[t], t});
			s.erase({H[i], i});
		}
	}
	{
		set <pii> s;
		for (int i=1;i<K;i++) s.insert({H[i], i});
		for (int i=1;i<=N;i++){
			int t = (i+K-2)%N+1;
			auto it = s.lower_bound({H[t], 0});
			if (it != s.begin()){
				it--;
				nxt_l[t][0] = (t - it->second + N) % N;
			}
			s.insert({H[t], t});
			s.erase({H[i], i});
		}
	}
	for (int i=0;i+1<18;i++) for (int j=1;j<=N;j++){
		nxt_l[j][i+1] = min(N+10, nxt_l[go_left(j, nxt_l[j][i])][i] + nxt_l[j][i]);
		nxt_r[j][i+1] = min(N+10, nxt_r[go_right(j, nxt_r[j][i])][i] + nxt_r[j][i]);
	}
}

bool has_left_path(int a, int b)
{
	int d = (a-b+N)%N;
	for (int i=18;i--;) if (d >= nxt_l[a][i]){
		d -= nxt_l[a][i];
		a = go_left(a, nxt_l[a][i]);
	}
	return (a-b+N)%N < K && H[a] >= H[b];
}

bool has_right_path(int a, int b)
{
	int d = (b-a+N)%N;
	for (int i=18;i--;) if (d >= nxt_r[a][i]){
		d -= nxt_r[a][i];
		a = go_right(a, nxt_r[a][i]);
	}
	return (b-a+N)%N < K && H[a] >= H[b];
}

int compare_plants(int a, int b)
{
	a++; b++;
	if (has_left_path(a, b) || has_right_path(a, b)) return 1;
	if (has_left_path(b, a) || has_right_path(b, a)) return -1;
	return 0;
}

Compilation message (stderr)

plants.cpp: In instantiation of 'SegTree<T>::SegTree(int*) [with T = int]':
plants.cpp:101:25:   required from here
plants.cpp:23:19: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   23 |   TS = 1 << n_bits+1; ST = TS/2-1;
      |             ~~~~~~^~

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