Submission #1246047

#	Time	Username	Problem	Language	Result	Execution time	Memory
1246047		nqknht	Jakarta Skyscrapers (APIO15_skyscraper)	C++20	57 / 100	77 ms	123720 KiB

skyscraper

#include <bits/stdc++.h>

#define ll long long
#define fi first
#define se second
#define len(s) (ll)s.size()

const ll I = 2e5 + 9;
const ll Z = 998244353;

using namespace std;

int n, m;

namespace subfull
{
    vector<pair<pair<int, int>, int>> adj[5009][230];
    priority_queue<pair<ll, pair<int, int>>> pq;
    bool check[50008][230];
    ll dis[50008][230];

    void addEd(ll u, ll xu, ll v, ll xv, ll w)
    {
        adj[u][xu].push_back({{v, xv}, w});
    }
    void solve()
    {
        ll sav, root;
        for (ll i = 1; i <= m; i++)
        {
            ll pos, power;
            cin >> pos >> power;
            if (i == 2)
                sav = pos;
            if (i == 1)
                root = pos;
            if (power >= sqrt(n))
            {
                for (ll j = pos - power, w = 1; j >= 0; j -= power, w++)
                    adj[pos][0].push_back({{j, 0}, w});
                for (ll j = pos + power, w = 1; j < n; j += power, w++)
                    adj[pos][0].push_back({{j, 0}, w});
                continue;
            }
            addEd(pos, power, pos, 0, 0);
            addEd(pos, 0, pos, power, 0);
            if (pos - power >= 0)
            {
                addEd(pos, power, pos - power, 0, 1);
                addEd(pos, power, pos - power, power, 1);
            }
            if (pos + power < n)
            {
                addEd(pos, power, pos + power, power, 1);
                addEd(pos, power, pos + power, 0, 1);
            }
        }
        memset(dis, 10, sizeof dis);
        dis[root][0] = 0;
        pq.push({0, {root, 0}});
        ll rs = dis[1][1];
        while (!pq.empty())
        {
            ll af = pq.top().se.fi, as = pq.top().se.se;
            pq.pop();
            if (check[af][as])
                continue;
            check[af][as] = true;
            if (af == sav)
                rs = min(rs, dis[af][as]);
            if (as != 0)
            {
                if (af + as < n && dis[af + as][as] > dis[af][as] + 1)
                {
                    dis[af + as][as] = dis[af][as] + 1;
                    pq.push({-dis[af + as][as], {af + as, as}});
                }
                if (af - as >= 0 && dis[af - as][as] > dis[af][as] + 1)
                {
                    dis[af - as][as] = dis[af][as] + 1;
                    pq.push({-dis[af - as][as], {af - as, as}});
                }
                if (dis[af][0] > dis[af][as])
                {
                    dis[af][0] = dis[af][as];
                    pq.push({-dis[af][0], {af, 0}});
                }
            }
            for (auto z : adj[af][as])
            {
                if (dis[z.fi.fi][z.fi.se] > dis[af][as] + z.se)
                {
                    dis[z.fi.fi][z.fi.se] = dis[af][as] + z.se;
                    pq.push({-dis[z.fi.fi][z.fi.se], {z.fi.fi, z.fi.se}});
                }
            }
        }
        cout << (rs < 1000000000 ? rs : -1);
    }
}

int main()
{
#define TN "sky"
    if (fopen(TN ".inp", "r"))
    {
        freopen(TN ".inp", "r", stdin);
        freopen(TN ".out", "w", stdout);
    }
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> m;
    subfull::solve();
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:107:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |         freopen(TN ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:108:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |         freopen(TN ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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