제출 #847118

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
847118		vjudge1	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	0 / 100	3 ms	21912 KiB

skyscraper

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

using pii = pair<int, int>;

const int N = 3e4 + 5;
const int oo = 1e9;
const int SQRT = 175;

#define eb emplace_back

struct node {
    int w, u, dir;

    node() {
        w = u = dir = 0;
    }

    node(int w, int u, int dir) : w(w), u(u), dir(dir) {}

    friend bool operator > (node a, node b) {
        return a.w > b.w;
    }
};

int n, m;
int dist[N][SQRT];
pii a[N];
vector<int> adj[N];
priority_queue<node, vector<node>, greater<node>> Q;

void update(int u, int v, int w, int dir,int pre) {
    if(dist[v][dir] > dist[u][pre] + w) {
        dist[v][dir] = dist[u][pre] + w;
        Q.emplace(dist[v][dir], v, dir);
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> m;

    for(int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].eb(v);
        a[i] = {u, v};
    }

    memset(dist, 0x3f, sizeof dist);
    dist[a[0].first][0] = 0;
    Q.emplace(0, a[0].first, 0);

    while(!Q.empty()) {
        node top = Q.top();
        Q.pop();
        int u = top.u;
        int dir = top.dir;

        if(top.w != dist[u][dir])
            continue;

        //cout << u << ' ' << dir << '\n';
        if(dir) {
            if(u + dir <= n)
                update(u, u + dir, 1, dir, dir);

            if(u - dir >= 0)
                update(u, u - dir, 1, dir, dir);

            update(u, u, 0, 0 , dir);
        }

        for(int v : adj[u]) {
            if(v >= SQRT) {
                for(int j = 1; u + j * v <= n; j++)
                    update(u, u + j * v, j, 0, 0);

                for(int j = 1; u - j * v >= 0; j++)
                    update(u, u - j * v, j, 0, 0);

            } else {
                if(u + v <= n)
                    update(u, u + v, 1, v , 0);

                if(u - v >= 0)
                    update(u, u - v, 1, v , 0);
            }
        }
    }
    int res = 1e9;
    for (int i = 0 ; i < SQRT; ++i) {
        res = min(res , dist[a[1].first][i]);
//        cout << dist[1][i] << '\n';
    }
    cout << res;
}
/*
5 3
0 2
1 1
4 1
*/

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