Submission #420197

#	Time	Username	Problem	Language	Result	Execution time	Memory
420197		meatrow	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	22 / 100	7 ms	6476 KiB

skyscraper

// #pragma GCC target ("avx2")
// #pragma GCC optimization ("O3")
#include <bits/stdc++.h>
 
using namespace std;
 
using ll = long long;
using ld = long double;
 
const int MOD = 1e9 + 7;
 
ll binpow(ll a, ll p, int mod = MOD) {
    ll res = 1;
    while (p) {
        if (p & 1) {
            (res *= a) %= mod;
        }
        p >>= 1;
        (a *= a) %= mod;
    }
    return res;
}
 
ll gcd(ll a, ll b) {
    return b == 0 ? a : gcd(b, a % b);
}

const int N = 30005;
const int M = 600;

int dist[N][M + 1];
set<int> doges[N];

void solve() {
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
        fill(dist[i], dist[i] + M + 1, 1e9);
    }

    pair<int, int> start;
    int finish;
    for (int i = 0; i < m; i++) {
        int b, p;
        cin >> b >> p;
        doges[b].insert(p);
        if (i == 0) {
            start = {b, p};
            dist[b][p] = 0;
        }
        if (i == 1) {
            finish = b;
        }
    }

    set<pair<int, pair<int, int>>> setik;
    setik.insert({0, start});
    while (!setik.empty()) {
        int v, p;
        tie(v, p) = setik.begin()->second;
        setik.erase(setik.begin());
        if (p == M) {
            for (int doge : doges[v]) {
                if (doge < M) {
                    if (dist[v][p] < dist[v][doge]) {
                        setik.erase({dist[v][doge], {v, doge}});
                        dist[v][doge] = dist[v][p];
                        setik.insert({dist[v][doge], {v, doge}});
                    }
                } else {
                    for (int i = v % doge; i < n; i += doge) {
                        if (dist[v][p] + abs(v - i) / doge < dist[v][M]) {
                            setik.erase({dist[v][M], {v, M}});
                            dist[v][M] = dist[v][p] + abs(v - i) / doge;
                            setik.insert({dist[v][M], {v, M}});
                        }
                    }
                }
            }
            continue;
        }

        if (v + p < n && dist[v][p] + 1 < dist[v + p][p]) {
            setik.erase({dist[v + p][p], {v + p, p}});
            dist[v + p][p] = dist[v][p] + 1;
            setik.insert({dist[v + p][p], {v + p, p}});
        }
        if (v - p >= 0 && dist[v][p] + 1 < dist[v - p][p]) {
            setik.erase({dist[v - p][p], {v - p, p}});
            dist[v - p][p] = dist[v][p] + 1;
            setik.insert({dist[v - p][p], {v - p, p}});
        }
        if (dist[v][p] < dist[v][M]) {
            setik.erase({dist[v][M], {v, M}});
            dist[v][M] = dist[v][p];
            setik.insert({dist[v][M], {v, M}});
        }
    }

    int ans = *min_element(dist[finish], dist[finish] + M + 1);
    if (ans == 1e9) ans = -1;
    cout << ans << endl;
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T = 1;
    // cin >> T;
    for (int tc = 1; tc <= T; tc++) {
        // cout << "Case #" << tc << ": ";
        solve();
    }
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void solve()':
skyscraper.cpp:42:9: warning: 'finish' may be used uninitialized in this function [-Wmaybe-uninitialized]
   42 |     int finish;
      |         ^~~~~~

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