Submission #107935

#	Time	Username	Problem	Language	Result	Execution time	Memory
107935		dfistric	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	480 ms	63388 KiB

skyscraper

#include <bits/stdc++.h>

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) FOR(i, 0, n)
#define ll long long

using namespace std;

const int MAXN = 30010;
int B[MAXN], P[MAXN];
int n, m;
vector <pair <int, int> > ve[MAXN];
set <pair <int, int> > se;
int dist[MAXN];
set <int> E[MAXN];

int main() {
    ios_base::sync_with_stdio(false);

    cin >> n >> m;

    REP(i, m) {
        cin >> B[i] >> P[i];
        E[B[i]].insert(P[i]);
    }

    REP(i, n) {
        for (int t : E[i]) {
            int c = 1;
            while (i + t * c < n) {
                int j = i + t * c;
                ve[i].push_back({j, c});
                if (E[j].find(c) != E[j].end()) break;
                c++;
            }
            
            c = 1;
            while (i - t * c >= 0) {
                int j = i - t * c;
                ve[i].push_back({j, c});
                if (E[j].find(c) != E[j].end()) break;
                c++;
            }
        }
    }

    REP(i, n) dist[i] = 1e9;
    dist[B[0]] = 0;
    REP(i, n) se.insert({dist[i], i});
    
    while (se.size()) {
        auto tr = *se.begin();
        se.erase(se.begin());

        int x = tr.second, D = tr.first;
        if (x == B[1]) break;

        for (auto t : ve[x]) {
            int y = t.first, d = t.second;
            if (dist[y] > D + d) {
                se.erase({dist[y], y});
                dist[y] = D + d;
                se.insert({dist[y], y});
            }
        }
    }

    if (dist[B[1]] >= 1e9) cout << "-1\n";
    else                   cout << dist[B[1]] << "\n";

    return 0;
}

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