Submission #589735

#	Time	Username	Problem	Language	Result	Execution time	Memory
589735		Lucpp	Comparing Plants (IOI20_plants)	C++17	49 / 100	970 ms	33364 KiB

plants

#include "plants.h"
#include <bits/stdc++.h>
using namespace std;
const int INF = 1e8;
int n, k;
vector<int> dpL, dpR;

void init_k2(vector<int> r){
	dpL.resize(n), dpR.resize(n);
	for(int it = 0; it < 2; it++){
		for(int i = n-1; i >= 0; i--){
			if(r[i]) dpR[i] = dpR[(i+1)%n]+1;
		}
		for(int i = 0; i < n; i++){
			if(!r[(i+n-1)%n]) dpL[i] = dpL[(i+n-1)%n]+1;
		}
	}
}

struct Data{
	int m = INF, l, r, ind = -1;
};
Data combine(Data a, Data b){
	Data d;
	d.m = min(a.m, b.m);
	if(d.m == a.m) d.l = a.l;
	else d.l = b.l;
	if(d.m == b.m) d.r = b.r;
	else d.r = a.r;
	if(d.m == a.m && a.ind != -1) d.ind = a.ind;
	if(d.m == b.m && b.ind != -1) d.ind = b.ind;
	if(d.m == a.m && d.m == b.m && b.l-a.r >= k) d.ind = b.l;
	return d;
}
int cap;
vector<Data> S;
vector<int> O;
vector<bool> lazy;
void build(vector<int> v){
	for(cap = 1; cap < (int)v.size(); cap *= 2);
	S.resize(2*cap);
	O.resize(2*cap);
	lazy.resize(2*cap);
	for(int i = 0; i < (int)v.size(); i++) S[i+cap] = Data{v[i], i+1, i+1};
	for(int i = cap-1; i > 0; i--) S[i] = combine(S[2*i], S[2*i+1]);
}
void apply(int v, int i){
	lazy[i] = true;
	O[i] += v;
	S[i].m += v;
}
void push(int i){
	if(lazy[i]){
		apply(O[i], 2*i);
		apply(O[i], 2*i+1);
		O[i] = 0;
		lazy[i] = false;
	}
}
void upd(int p, int v, int a, int b, int i){
	if(a == b) S[i] = {v, p, p, -1};
	else{
		push(i);
		int m = (a+b)/2;
		if(p <= m) upd(p, v, a, m, 2*i);
		else upd(p, v, m+1, b, 2*i+1);
		S[i] = combine(S[2*i], S[2*i+1]);
	}
}
void apply(int l, int r, int v, int a, int b, int i){
	if(l <= a && b <= r) apply(v, i);
	else if(b < l || r < a) return;
	else{
		push(i);
		int m = (a+b)/2;
		apply(l, r, v, a, m, 2*i);
		apply(l, r, v, m+1, b, 2*i+1);
		S[i] = combine(S[2*i], S[2*i+1]);
	}
}

vector<int> h;
void init_else(vector<int> r){
	h.resize(2*n);
	r.resize(2*n);
	for(int i = 0; i < n; i++) r[i+n] = r[i];
	build(r);
	for(int it = 0; it < n; it++){
		assert(S[1].m == 0);
		assert(S[1].ind != -1);
		int i = S[1].ind;
		i = (i-1)%n;
		h[i] = h[i+n] = n-it;
		upd(i+1, INF, 1, cap, 1);
		upd(i+n+1, INF, 1, cap, 1);
		apply(max(0, i-k+1)+1, i, -1, 1, cap, 1);
		apply(i+n-k+2, i+n, -1, 1, cap, 1);
		apply(i+2*n-k+2, 2*n, -1, 1, cap, 1);
	}
}

void init(int K, vector<int> r) {
	k = K;
	n = (int)r.size();
	if(k == 2) init_k2(r);
	else init_else(r);
}

int compare_k2(int x, int y){
	int d1 = (y-x+n)%n;
	int d2 = n-d1;
	if(dpR[x] >= d1 || dpL[x] >= d2) return -1;
	if(dpR[y] >= d2 || dpL[y] >= d1) return 1;
	return 0;
}

int compare_else(int x, int y){
	if(h[x] < h[y]) return -1;
	else return 1;
}

int compare_plants(int x, int y) {
	if(k == 2) return compare_k2(x, y);
	else return compare_else(x, y);
}

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