Submission #466635

#	Time	Username	Problem	Language	Result	Execution time	Memory
466635		rainboy	Rainforest Jumps (APIO21_jumps)	C++17	100 / 100	1336 ms	22184 KiB

jumps

#include "jumps.h"
#include <vector>

using namespace std;

const int N = 200000;

typedef vector<int> vi;

int max(int a, int b) { return a > b ? a : b; }

int aa[N], qu[N];
int ddp[N], pp[N], pp_[N];
int ddq[N], qq[N], qq_[N];
int ddl[N], ll[N], ll_[N];
int ddr[N], rr[N], rr_[N];
int n;

void dfs(int *dd, int *pp, int *pp_, int i) {
	if (dd[i])
		return;
	if (pp[i] == -1)
		dd[i] = 1, pp_[i] = -1;
	else {
		int p, p_;

		dfs(dd, pp, pp_, pp[i]);
		p = pp[i], p_ = pp_[p];
		dd[i] = dd[p] + 1, pp_[i] = dd[p] - dd[pp_[p]] != dd[p_] - dd[pp_[p_]] ? p : pp_[p_];
	}
}

void init(int n_, vi aa_) {
	int i, cnt;

	n = n_;
	for (i = 0; i < n; i++)
		aa[i] = aa_[i];
	cnt = 0;
	for (i = 0; i < n; i++) {
		while (cnt && aa[qu[cnt - 1]] < aa[i])
			cnt--;
		ll[i] = cnt == 0 ? -1 : qu[cnt - 1];
		qu[cnt++] = i;
	}
	cnt = 0;
	for (i = n - 1; i >= 0; i--) {
		while (cnt && aa[qu[cnt - 1]] < aa[i])
			cnt--;
		rr[i] = cnt == 0 ? -1 : qu[cnt - 1];
		qu[cnt++] = i;
	}
	for (i = 0; i < n; i++) {
		pp[i] = ll[i] == -1 || rr[i] == -1 ? (ll[i] == -1 ? rr[i] : ll[i]) : (aa[ll[i]] < aa[rr[i]] ? ll[i] : rr[i]);
		qq[i] = ll[i] == -1 || rr[i] == -1 ? (ll[i] == -1 ? rr[i] : ll[i]) : (aa[ll[i]] > aa[rr[i]] ? ll[i] : rr[i]);
	}
	for (i = 0; i < n; i++) {
		dfs(ddp, pp, pp_, i);
		dfs(ddq, qq, qq_, i);
		dfs(ddl, ll, ll_, i);
		dfs(ddr, rr, rr_, i);
	}
}

int minimum_jumps(int w, int x, int y, int z) {
	int i, j, k, a;

	j = y;
	while (1)
		if (rr_[j] != -1 && rr_[j] <= z)
			j = rr_[j];
		else if (rr[j] != -1 && rr[j] <= z)
			j = rr[j];
		else
			break;
	i = x;
	while (1)
		if (ll_[i] != -1 && ll_[i] >= w && aa[ll_[i]] < aa[j])
			i = ll_[i];
		else if (ll[i] != -1 && ll[i] >= w && aa[ll[i]] < aa[j])
			i = ll[i];
		else
			break;
	if (aa[i] > aa[j])
		return -1;
	a = -1;
	if (x + 1 < y) {
		k = x + 1;
		while (1)
			if (rr_[k] != -1 && rr_[k] < y)
				k = rr_[k];
			else if (rr[k] != -1 && rr[k] < y)
				k = rr[k];
			else
				break;
		a = aa[k];
	}
	if (a > aa[j])
		return -1;
	k = 0;
	while (1)
		if (qq_[i] != -1 && aa[qq_[i]] <= a)
			k += ddq[i] - ddq[qq_[i]], i = qq_[i];
		else if (qq[i] != -1 && aa[qq[i]] <= a)
			k++, i = qq[i];
		else
			break;
	if (qq[i] != -1 && aa[qq[i]] <= aa[j])
		return k + (rr[i] != -1 && rr[i] >= y ? 1 : 2);
	while (1)
		if (pp_[i] != -1 && aa[pp_[i]] <= a)
			k += ddp[i] - ddp[pp_[i]], i = pp_[i];
		else if (pp[i] != -1 && aa[pp[i]] <= a)
			k++, i = pp[i];
		else
			break;
	if (pp[i] != -1 && aa[pp[i]] <= aa[j])
		return k + (rr[i] != -1 && rr[i] >= y ? 1 : 2);
	return -1;
}

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 13 / 13
• Subtask 4: 12 / 12
• Subtask 5: 23 / 23
• Subtask 6: 21 / 21
• Subtask 7: 19 / 19