제출 #482761

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
482761		jalsol	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	173 ms	68036 KiB

skyscraper

#ifdef LOCAL
#include "local.h"
#else
#include <bits/stdc++.h>
#define debug(...)
#define DB(...)
#endif

using namespace std;

const bool __initialization = []() {
    cin.tie(nullptr)->sync_with_stdio(false);
#define TASK "empty"
    if (fopen(TASK".inp", "r")) {
        (void)(!freopen(TASK".inp", "r", stdin));
        (void)(!freopen(TASK".out", "w", stdout)); }
    cout << setprecision(12) << fixed;
    return true;
}();

using ll = long long;
using ld = long double;

#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

#define For(i, l, r) for (int i = (l); i <= (r); ++i)
#define Ford(i, r, l) for (int i = (r); i >= (l); --i)
#define Rep(i, n) For (i, 0, (n) - 1)
#define Repd(i, n) Ford (i, (n) - 1, 0)
#define Fe(...) for (auto __VA_ARGS__)

template <class C> inline int isz(const C& c) { return static_cast<int>(c.size()); }
template <class T> inline bool chmin(T& a, const T& b) { return (a > b) ? a = b, true : false; }
template <class T> inline bool chmax(T& a, const T& b) { return (a < b) ? a = b, true : false; }

constexpr ld eps = 1e-9;
constexpr int inf = 1e9;
constexpr ll linf = 1e18;

// =============================================================================

constexpr int maxn = 3e4 + 5;

struct Link {
    int v, c;
};

struct State {
    int u, du;

    bool operator<(const State& o) const {
        return du > o.du;
    }
};

int len, n;
int a[maxn], pw[maxn];

set<int> building[maxn];
vector<Link> g[maxn];

int d[maxn];
priority_queue<State> q;

void Dijkstra() {
    memset(d, 0x3e, sizeof(int) * len);
    d[a[0]] = 0;
    q.push({a[0], d[a[0]]});

    while (isz(q)) {
        auto [u, du] = q.top(); q.pop();
        if (du != d[u]) continue;

        Fe (&[v, c] : g[u]) {
            if (chmin(d[v], d[u] + c)) {
                q.push({v, d[v]});
            }
        }
    }
}

signed main() {
    cin >> len >> n;
    Rep (i, n) cin >> a[i] >> pw[i];

    Rep (i, n) {
        building[a[i]].insert(pw[i]);
    }

    Rep (i, len) {
        Fe (p : building[i]) {
            for (int other = i + p; other < len; other += p) {
                g[i].push_back({other, (other - i) / p});
                if (building[other].count(p)) break;
            }
            for (int other = i - p; other >= 0; other -= p) {
                g[i].push_back({other, (i - other) / p});
                if (building[other].count(p)) break;
            }
        }
    }

    Dijkstra();
    int ans = d[a[1]];
    if (ans >= inf) ans = -1;
    cout << ans << '\n';
}

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