제출 #725930

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
725930		PixelCat	Sky Walking (IOI19_walk)	C++14	15 / 100	187 ms	70572 KiB

walk

#include "walk.h"
#ifdef NYAOWO
#include "grader.cpp"
#endif

#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i <= b; i++)
#define Forr(i,a, b) for(int i = a; i >= b; i--)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
#define eb emplace_back
#define int LL
using namespace std;
using LL = long long;
using pii = pair<int, int>;
using Vi = vector<int32_t>;

const int MAXN = 100010;
const int INF = 1e18;

int n, m;

Vi st[MAXN], ed[MAXN];
int solve_1n(Vi x, Vi h, Vi l, Vi r, Vi y) {
    For(i, 0, m - 1) {
        st[l[i]].eb(y[i]);
        ed[r[i]].eb(y[i]);
    }
    map<int, int> mp;
    mp[0] = INF; mp[INF] = INF;
    for(auto &i:st[0]) mp[i] = i;
    auto eval = [&](int p, int hei) {
        auto it1 = mp.upper_bound(p);
        auto it2 = prev(it1);
        int res = p - (it2->F) + (it2->S);
        if(it1->F <= hei) {
            res = min(res, (it1->F) - p + (it1->S));
        }
        // cout << (it1->F) << " " << (it1->S) << "\n";
        // cout << (it2->F) << " " << (it2->S) << "\n";
        return res;
    };
    For(i, 1, n - 2) {
        set<int> upd;
        for(auto &j:st[i]) {
            int k = eval(j, h[i]);
            mp[j] = k;
            upd.insert(j);
        }
        for(auto &j:ed[i]) if(!upd.count(j)) {
            mp.erase(j);
        }
        // for(auto &p:mp) cout << p.F << " " << p.S << "\n";
        // cout << "\n";
    }
    // cout << "\n";
    // for(auto &p:mp) cout << p.F << " " << p.S << "\n";
    // cout << "\n";
    int ans = eval(0, h[n - 1]) + x.back() - x[0];
    if(ans >= INF) return -1;
    return ans;
}

const int MAXND = 2000010;
int nd_count = 0;
vector<pii> adj[MAXND];
int dist[MAXND];
int solve(Vi x, Vi h, Vi l, Vi r, Vi Y, int s, int g) {
    For(i, 0, m - 1) {
        st[l[i]].eb(Y[i]);
        ed[r[i]].eb(Y[i]);
    }
    map<int, pii> mp; // {y, {x, id}}
    map<pii, int> nodes;
    auto new_node = [&](int x1, int y1) {
        auto p = pii(x1, y1);
        if(nodes.count(p)) return nodes[p];
        nd_count++;
        nodes[p] = nd_count;
        return nd_count;
    };
    auto link = [&](int a, int b, int c) {
        adj[a].eb(b, c);
        adj[b].eb(a, c);
    };
    For(i, 0, n - 1) {
        vector<int> aly(1, 0);
        new_node(x[i], 0);
        for(auto &p:mp) {
            if(p.F > h[i]) break;
            aly.eb(p.F);
            int id = new_node(x[i], p.F);
            link(id, p.S.S, x[i] - p.S.F);
            p.S.F = x[i];
            p.S.S = id;
        }
        for(auto &y:ed[i]) {
            mp.erase(y);
        }
        for(auto &y:st[i]) {
            aly.eb(y);
            int id = new_node(x[i], y);
            mp[y] = pii(x[i], id);
        }
        sort(all(aly));
        // for(auto &p:aly) cout << p << " ";
        // cout << "\n";
        For(j, 1, sz(aly) - 1) {
            int y1 = aly[j - 1];
            int y2 = aly[j];
            int nd1 = new_node(x[i], y1);
            int nd2 = new_node(x[i], y2);
            link(nd1, nd2, y2 - y1);
            // cout << nd1 << " " << nd2 << " " << y2 - y1 << "\n";
        }
    }
    // for(auto &i:nodes) {
    //     cout << "(" << i.F.F << ", " << i.F.S << ") = " << i.S << "\n";
    // }
    memset(dist, -1, sizeof(dist));
    priority_queue<pii, vector<pii>, greater<pii>> pq; // dist, id
    pq.emplace(0, new_node(x[s], 0));
    int target = new_node(x[g], 0);
    while(!pq.empty()) {
        int d, id;
        tie(d, id) = pq.top(); pq.pop();
        if(dist[id] != -1) continue;
        if(id == target) return d;
        dist[id] = d;
        // cout << id << " " << d << "\n";
        for(auto &e:adj[id]) if(dist[e.F] == -1) {
            pq.emplace(d + e.S, e.F);
        }
    }
    return -1;
}

long long min_distance(Vi x, Vi h, Vi l, Vi r, Vi y, int32_t s, int32_t g) {
	n = sz(x);
    m = sz(l);
    return solve_1n(x, h, l, r, y);
    // return solve(x, h, l, r, y, s, g);
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 14
• Subtask 3: 15 / 15
• Subtask 4: 0 / 18
• Subtask 5: 0 / 43