Submission #279517

#	Time	Username	Problem	Language	Result	Execution time	Memory
279517		srvlt	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	22 / 100	160 ms	262148 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, ind[n0][m0];
vector <int> g[n0];
array <int, 2> t[k0];

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 = t[v][0], j = t[v][1];
			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 < n; i++)
		ind[i][m] = k++;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			ind[i][j] = k++;
			t[k - 1] = {i, j};
		}
	}
	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: 0 / 14
• Subtask 4: 0 / 21
• Subtask 5: 0 / 43