Submission #279527

#	Time	Username	Problem	Language	Result	Execution time	Memory
279527		srvlt	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	36 / 100	1105 ms	236408 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pb push_back
#define all(x) begin(x), end(x)
#define SZ(x) (int)(x).size()
#define cps(x) sort(all(x)), (x).erase(unique(all(x)), end(x))
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int n0 = 2003, m0 = 30003;
const int k0 = n0 * m0;
int n, m, b[m0], p[m0], k, d[k0], inf;
vector <int> g[n0];

int ind(int x, int y) {
	if (y == m) return x;
	return n + x * m + y;
}

void rev(int x, int & i, int & j) {
	if (x < n) {
		i = x, j = m;
		return;
	}
	x -= n;
	i = x / m;
	j = x - i * m;
}

void bfs(int x, int y) {
	memset(& d, 0x3f, sizeof(d));
	inf = d[0];
	deque <int> q;
	d[ind(x, y)] = 0;
	q.push_front(ind(x, y));
	while (!q.empty()) {
		int v = q.front();
		q.pop_front();
		if (v < n) {
			for (int to : g[v]) {
				if (d[to] > d[v]) {
					d[to] = d[v];
					q.push_front(to);
				}
			}
		}	else {
			int i, j;
			rev(v, i, j);
			if (i - p[j] >= 0) {
				int to = ind(i - p[j], j);
				if (d[to] > d[v] + 1) {
					d[to] = d[v] + 1;
					q.pb(to);
				}
			}
			if (i + p[j] < n) {
				int to = ind(i + p[j], j);
				if (d[to] > d[v] + 1) {
					d[to] = d[v] + 1;
					q.pb(to);
				}
			}
			int to = ind(i, m);
			if (d[to] > d[v]) {
				d[to] = d[v];
				q.push_front(to);
			}
		}
	}
}

int main() {
	ios_base::sync_with_stdio(false), cin.tie(NULL);
	cin >> n >> m;
	for (int i = 0; i < m; i++)
		cin >> b[i] >> p[i];
	for (int i = 0; i < m; i++)
		g[ind(b[i], m)].pb(ind(b[i], i));
	bfs(b[0], 0);
	int res = d[ind(b[1], 1)];
	if (res == inf) res = -1;
	cout << res;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 0 / 21
• Subtask 5: 0 / 43