Submission #110245

#	Time	Username	Problem	Language	Result	Execution time	Memory
110245		hugo_pm	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	940 ms	96520 KiB

skyscraper

#pragma GCC optimize("O3")
#pragma GCC target("sse2,sse3,ssse3,sse4,avx,avx2,tune=native")
#include <bits/stdc++.h>
using namespace std;
 
#define form2(i, a, b) for (int i = (a); i < (b); ++i)
#define ford2(i, a, b) for (int i = (a-1); i >= (b); --i)
#define form(i, n) form2(i, 0, n)
#define ford(i, n) ford2(i, n, 0)
 
#define chmax(x, v) x = max(x, (v))
#define chmin(x, v) x = min(x, (v))
#define fi first
#define se second
 
const int BIG = 2*(int)(1e9);
 
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
 
void solve();
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	solve();
	return 0;
}
 
const int borneSuj = 30*1000 + 5;
const int borneTab = 200*borneSuj;
int gt[borneSuj][200];
int inv[borneTab];
bool witPrev[borneTab];
bool witSuiv[borneTab];
 
int arr = -1, dep=-1;
 
int nbPlaces, nbDoges, nbNoeuds;
int limSqd;
 
vector<int> doge[borneSuj];
 
void solve()
{
	cin >> nbPlaces >> nbDoges;
	chmax(nbPlaces, 20);
	nbNoeuds = nbPlaces;
	limSqd = sqrt(nbPlaces);
 
	form2(distance, 1, limSqd) {
		form(ini, distance) {
			for (int place = ini; place < nbPlaces; place += distance) {
				int corNod = nbNoeuds; ++nbNoeuds;
				inv[corNod] = place+1;
				gt[place][distance] = corNod;
 
				if (place != ini) {
					witPrev[corNod] = true;
					witSuiv[corNod-1] = true;
				}
			}
		}
	}
 
	form(iDoge, nbDoges) {
		int pos, saut;
		cin >> pos >> saut;
		if (iDoge == 0) dep = pos;
		if (iDoge == 1) arr = pos;
		doge[pos].push_back(saut);
	}
	
	vector<int> md(nbNoeuds, BIG);
	vector<int> etat(nbNoeuds, 2);
	deque<int> m1;

	m1.push_front(dep);
	md[dep] = 0;

	while (! m1.empty()) {
		int nod = m1.front(); m1.pop_front();
		etat[nod] = 0;
		int dis = md[nod];
 
 		auto propag = [&] (int vo, int poids) {
			if (etat[vo] == 2) {
				m1.push_back(vo);
				etat[vo] = 1;
				md[vo] = dis + poids;
			} else if (etat[vo] == 1) {
				chmin(md[vo], dis + poids);
			} else {
				if (dis+poids < md[vo]) {
					md[vo] = dis+poids;
					etat[vo] = 1;
					m1.push_back(vo);
				}
			}
		};
 
		if (nod < nbPlaces) {
			int pos = nod;
			for (int saut : doge[nod]) {
				if (saut < limSqd) {
					propag(gt[pos][saut], 0);
				} else {
					for (int dd = 1; pos + dd*saut < nbPlaces; ++dd) {
						propag(pos+dd*saut, dd);
					}
		 
					for (int dd = 1; pos - dd*saut >= 0; ++dd) {
						propag(pos-dd*saut, dd);
					}
				}
			}
		}
 
		if (nod >= nbPlaces) {
			if (inv[nod]) propag(inv[nod]-1, 0);
			if (witPrev[nod]) propag(nod-1, 1);
			if (witSuiv[nod]) propag(nod+1, 1);
		}
	}
 
	if (md[arr] == BIG) cout << "-1\n";
	else cout << md[arr] << "\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 43 / 43