Submission #1110804

#	Time	Username	Problem	Language	Result	Execution time	Memory
1110804		CodeLakVN	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	161 ms	71988 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;

#define Task "SKY"
#define ll long long
#define pb push_back
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FOD(i, a, b) for (int i = (a); i >= (b); i--)
#define F first
#define S second

typedef pair<int, int> ii;

const int N = 5e4 + 6;
const int INF = 1e9;
const int MOD = 1e9 + 7;

template<class X, class Y>
    bool minimize(X &x, Y y) {
        if (x > y) {
            x = y;
            return true;
        } else return false;
    }

template<class X, class Y>
    bool maximize(X &x, Y y) {
        if (x < y) {
            x = y;
            return true;
        } else return false;
    }

int n, m;
vector<set<int>> powers;
int dist[N];
vector<pair<int, int>> adj[N];
int s, e;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    if (fopen(Task".INP", "r")) {
        freopen(Task".INP", "r", stdin);
        freopen(Task".OUT", "w", stdout);
    }

    cin >> n >> m;
    powers.resize(n + 1);
    FOR(i, 0, m - 1) {
        int building, power;
        cin >> building >> power;
        powers[building].insert(power);

        if (i == 0) s = building;
        if (i == 1) e = building;
    }

    FOR(i, 0, n - 1) {
        for (int power : powers[i]) {
            FOR(j, 1, (n - i) / power) {
                int nxt = i + j * power;
                adj[i].push_back({nxt, j});
                if (powers[nxt].count(power)) break;
            }
            FOR(j, 1, i / power) {
                int nxt = i - j * power;
                if (nxt < 0) break;
                adj[i].push_back({nxt, j});
                if (powers[nxt].count(power)) break;
            }
        }
    }

    priority_queue<ii, vector<ii>, greater<ii>> pq;
    memset(dist, 0x3f, sizeof(dist));
    pq.push({0, s});
    dist[s] = 0;
    while(!pq.empty()) {
        auto [d, u] = pq.top();
        pq.pop();

        if (u == e) {
            cout << d;
            return 0;
        }

        if (d > dist[u]) continue;
        for (auto [v, w] : adj[u]) if (minimize(dist[v], dist[u] + w)) {
            pq.push({dist[v], v});
        }
    }
    cout << -1;

    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:44:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |         freopen(Task".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:45:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |         freopen(Task".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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