Submission #719910

#	Time	Username	Problem	Language	Result	Execution time	Memory
719910		joelgun14	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	0 / 100	4 ms	5332 KiB

skyscraper

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define mp make_pair
#define fi first
#define lb lower_bound
#define se second
#define endl "\n"
using namespace std;
struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};
int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    int n, m;
    cin >> n >> m;
    int blk = 100;
    vector<int> weights[n];
    int init = -1, initp = -1, target = -1;
    map<pair<int, int>, int> pti;
    set<int> s[(int)1e5];
    int t = 0;
    for(int i = 1; i <= blk; ++i) {
        for(int j = 0; j < i; ++j)
            pti[mp(j, i)] = t++;
    }
    bool done[n];
    memset(done, 0, sizeof(done));
    for(int i = 1; i <= m; ++i) {
        int b, p;
        cin >> b >> p;
        if(i == 1)
            init = b, initp = p;
        else if(i == 2)
            target = b;
        // b -> pos
        // p -> multiple
        weights[b].push_back(p);
        if(!done[b]) {
            for(int j = 1; j <= blk; ++j) {
                //cout << "INSERT " << b % j << " " << j << " " << b << endl;
                s[pti[mp(b % j, j)]].insert(b);
            }
            done[b] = 1;
        }
    }
    // gaperlu cek semua cukup cek yg ada weights
    // kalo udh proc weight jg gperlu
    // kalo <= blk maka memo tiap pair int modulo dalam vector
    // kalo > blk maka cek manual
    // doge cmn boleh gerak dr ori node (gaboleh meet di tengah)
    // hence cukup dijkstra dengan 1 origin, terus klo intersect lainnya bs langsung dijkstra aja
    // tiap node ada theoretically n^2 dijkstra state yg mgkn?
    // tp yg high modulo itu sparse, jadi bs simpan manual pakai sorted vector/semacamnya
    priority_queue<pair<int, pair<int, pair<int, int>>>, vector<pair<int, pair<int, pair<int, int>>>>, greater<pair<int, pair<int, pair<int, int>>>>> pq;
    // fi -> dist
    // se.fi -> idx
    // se.se.fi -> current p
    // se.se.se -> tanda dr atas/bawah
    // guna -> reduce double counting
    //cout << init << " " << initp << endl;
    pq.push(mp(0, mp(init, mp(initp, -1))));
    int d[n + 1];
    unordered_map<int, bool, custom_hash> vis[n];
    memset(d, -1, sizeof(d));
    // cek ada yg bs sampai ke target atau tidak, kalo tidak langsung output false
    // kalo iya, maka ada pembuktian min path tidak sepanjang itu?
    while(pq.size()) {
        int dist = pq.top().fi, idx = pq.top().se.fi, curp = pq.top().se.se.fi, tanda = pq.top().se.se.se;
        pq.pop();
        //cout << dist << " " << idx << endl;
        if(vis[idx][curp])
            continue;
        if(d[idx] == -1)
            d[idx] = dist;
        d[idx] = min(d[idx], dist);
        for(auto i : weights[idx]) {
            if(!vis[idx][i] && i != curp) {
                if(i > blk) {
                    int tmp = idx + i;
                    while(tmp < n && !weights[tmp].size())
                        tmp += i;
                    if(tmp < n && !vis[tmp][i])
                        pq.push(mp(dist + (tmp - idx) / i, mp(tmp, mp(i, 0))));
                    tmp = idx - i;
                    while(tmp >= 0 && !weights[tmp].size())
                        tmp -= i;
                    if(tmp >= 0 && !vis[tmp][i]) 
                        pq.push(mp(dist + (idx - tmp) / i, mp(tmp, mp(i, 1))));
                }
                else {
                    int mres = idx % i;
                    int x = pti[mp(mres, i)];
                    int nxtidx = -1, pridx = -1;
                    while(s[x].size() && s[x].lb(idx) != s[x].end()) {
                        int tmp = *s[x].lb(idx);
                        //cout << "FIND NXT " << tmp << " " << weights[tmp].size() << endl;
                        if(weights[tmp].size() && tmp != idx) {
                            nxtidx = tmp;
                            break;
                        }
                        s[x].erase(s[x].lb(idx));
                    }
                    while(s[x].size() && s[x].lb(idx) != s[x].begin()) {
                        int tmp = *--s[x].lb(idx);
                        if(weights[tmp].size() && tmp != idx) {
                            pridx = tmp;
                            break;
                        }
                        s[x].erase(--s[x].lb(idx));
                    }
                    //cout << nxtidx << " " <<pridx << endl;
                    if(nxtidx != -1 && !vis[nxtidx][i]) {
                        pq.push(mp(dist + (nxtidx - idx) / i, mp(nxtidx, mp(i, 0))));
                    }
                    if(pridx != -1 && !vis[pridx][i]) {
                        pq.push(mp(dist + (idx - pridx) / i, mp(pridx, mp(i, 1))));
                    }
                }
            }
            vis[idx][i] = 1;
        }
        weights[idx].clear();
        //cout << idx << " " << curp << endl;
        if(!vis[idx][curp]) {
            vis[idx][curp] = 1;
            //cout << curp << " " << blk << endl;
            if(curp > blk) {
                int tmp = idx + curp;
                if(tanda != 1) {
                    while(tmp < n && !weights[tmp].size())
                        tmp += curp;
                    if(tmp < n && !vis[tmp][curp])
                        pq.push(mp(dist + (tmp - idx) / curp, mp(tmp, mp(curp, 0))));
                }
                if(tanda != 0) {
                    tmp = idx - curp;
                    while(tmp >= 0 && !weights[tmp].size())
                        tmp -= curp;
                    if(tmp >= 0 && !vis[tmp][curp]) 
                        pq.push(mp(dist + (idx - tmp) / curp, mp(tmp, mp(curp, 1))));
                }
            }
            else {
                int mres = idx % curp;
                int x = pti[mp(mres, curp)];
                int nxtidx = -1, pridx = -1;
                while(s[x].size() && s[x].lb(idx) != s[x].end()) {
                    int tmp = *s[x].lb(idx);
                    if(weights[tmp].size() && tmp != idx) {
                        nxtidx = tmp;
                        break;
                    }
                    s[x].erase(s[x].lb(idx));
                }
                while(s[x].size() && s[x].lb(idx) != s[x].begin()) {
                    int tmp = *--s[x].lb(idx);
                    if(weights[tmp].size() && tmp != idx) {
                        pridx = tmp;
                        break;
                    }
                    s[x].erase(--s[x].lb(idx));
                }
                //cout << nxtidx << " " << pridx << endl;
                if(nxtidx != -1 && tanda != 1 && !vis[nxtidx][curp]) {
                    pq.push(mp(dist + (nxtidx - idx) / curp, mp(nxtidx, mp(curp, 0))));
                }
                if(pridx != -1 && tanda != 0 && !vis[pridx][curp]) {
                    pq.push(mp(dist + (idx - pridx) / curp, mp(pridx, mp(curp, 1))));
                }
            }
        }
        if(idx == target)
            break;
    }
    cout << d[target] << endl;
}

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