Submission #160836

#	Time	Username	Problem	Language	Result	Execution time	Memory
160836		lyc	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	566 ms	262148 KiB

skyscraper

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

typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef pair<ii, int> ri3;
#define mp make_pair
#define pb push_back
#define fi first
#define sc second
#define SZ(x) (int)(x).size()
#define ALL(x) begin(x), end(x) 
#define REP(i, n) for (int i = 0; i < n; ++i) 
#define FOR(i, a, b) for (int i = a; i <= b; ++i)
#define RFOR(i, a, b) for (int i = a; i >= b; --i)

const int MX_N = 30000;
const int MX_M = 30000;
const int MX_P = 30000;
const int SQ = sqrt(MX_P);

int N, M;
vector<ii> al[MX_N*(SQ+1)];
vector<int> doge[MX_M];
int dist[MX_N*(SQ+1)];
priority_queue<ii, vector<ii>, greater<ii> > pq;

int main() {
    //freopen("in.txt", "r", stdin);
    ios::sync_with_stdio(false);
    cin.tie(0);

    int N, M; cin >> N >> M;

    FOR(x,1,SQ){
        FOR(i,0,N-1){
            if (i+x < N) {
                al[x*N + i].emplace_back(x*N + i+x, 1);
                al[x*N + i+x].emplace_back(x*N + i, 1);
                //cout << "JOIN " << x << " :: " << i << " " << i+x << endl;
            }
            al[x*N + i].emplace_back(i, 0);
        }
    }

    int S, T;
    FOR(i,0,M-1){
        int B, P; cin >> B >> P;
        if (i == 0) S = B;
        else if (i == 1) T = B;

        if (P <= SQ) {
            al[B].emplace_back(P*N + B, 0);
        } else {
            doge[B].push_back(P);
        }
    }

    memset(dist,-1,sizeof dist);
    dist[S] = 0;
    pq.emplace(0,S);
    while (!pq.empty()) {
        int u = pq.top().sc, w = pq.top().fi; pq.pop();
        if (w > dist[u]) continue;
        //cout << "u " << u/N << " : " << u%N << " w " << w << endl;
        if (u == T) break;

        for (auto e : al[u]) {
            int v = e.fi, w = dist[u] + e.sc;
            if (dist[v] == -1 || w < dist[v]) {
                dist[v] = w;
                pq.emplace(dist[v], v);
            }
        }
        if (u < N) {
            for (auto p : doge[u]) {
                for (int i = 1; u - i*p >= 0; ++i) {
                    int v = u - i*p, w = dist[u] + i;
                    if (dist[v] == -1 || w < dist[v]) {
                        dist[v] = w;
                        pq.emplace(dist[v], v);
                    }
                }
                for (int i = 1; u + i*p < N; ++i) {
                    int v = u + i*p, w = dist[u] + i;
                    if (dist[v] == -1 || w < dist[v]) {
                        dist[v] = w;
                        pq.emplace(dist[v], v);
                    }
                }
            }
        }
    }

    cout << dist[T] << '\n';
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:68:9: warning: 'T' may be used uninitialized in this function [-Wmaybe-uninitialized]
         if (u == T) break;
         ^~

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