Submission #163681

#	Time	Username	Problem	Language	Result	Execution time	Memory
163681		Minnakhmetov	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	475 ms	74900 KiB

skyscraper

#include <bits/stdc++.h>
    
#define ll long long
#define all(aaa) aaa.begin(), aaa.end()
 
using namespace std;

struct E {
	int to, w;
};

const int N = 3e4 + 5, P = 70, V = N + N + N * P, INF = 1e9;
vector<E> g[N + N];
int d[V];

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);

    int n, m;
    cin >> n >> m;

    for (int i = 0; i < m; i++) {
    	int x, y;
    	cin >> x >> y;
    	g[m + x].push_back({i, 0});
    	g[i].push_back({m + x, 0});

    	if (y < P) {
    		g[i].push_back({n + m + x * P + y, 0});
    	}
    	else {
			int z = x - y, w = 1;
			while (z >= 0) {
				g[i].push_back({m + z, w});
				z -= y;
				w++;
			}
			z = x + y, w = 1;
			while (z < n) {
				g[i].push_back({m + z, w});
				z += y;
				w++;
			}
    	}
    }

    // for (int i = 0; i < n; i++) {
    // 	for (int j = 1; j < P; j++) {
    // 		int ver = n + m + i * P + j;
    // 		g[ver].push_back({m + i, 0});
    // 		if (i - j >= 0) {
    // 			g[ver].push_back({ver - j * P, 1});
    // 		}
    // 		if (i + j < n) {
    // 			g[ver].push_back({ver + j * P, 1});
    // 		}
    // 	}
    // }

    fill(d, d + V, INF);
    d[0] = 0;

    priority_queue<pair<int, int>, 
    			   vector<pair<int, int>>, 
    			   greater<pair<int, int>>> q;

    q.push({d[0], 0});

    while (!q.empty()) {
    	int node = q.top().second,
    		 cd = q.top().first;

    	q.pop();

    	if (cd != d[node])
    		continue;

    	if (node < n + m) {
			for (E e : g[node]) {
				if (d[e.to] > cd + e.w) {
					d[e.to] = cd + e.w;
					q.push({d[e.to], e.to});
				}
			}
    	}
    	else {
    		int x = (node - n - m) / P,
    			y = node - n - m - x * P;

    		if (d[m + x] > cd) {
    			d[m + x] = cd;
    			q.push({d[m + x], m + x});
    		}
    		if (x - y >= 0 && d[node - y * P] > cd + 1) {
    			d[node - y * P] = cd + 1;
    			q.push({d[node - y * P], node - y * P});
    		}
    		if (x + y < n && d[node + y * P] > cd + 1) {
    			d[node + y * P] = cd + 1;
    			q.push({d[node + y * P], node + y * P});
    		}
    	}
    }

    cout << (d[1] < INF ? d[1] : -1);

    return 0;
}

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