Submission #1191169

#	Time	Username	Problem	Language	Result	Execution time	Memory
1191169		countless	메기 농장 (IOI22_fish)	C++20	0 / 100	43 ms	12600 KiB

fish

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

typedef long long ll;
typedef long double ld;

const ll MOD = 998244353;
const ll INF = 1e18;
const ld EPS = 1e-12;

#define endl "\n"
#define sp <<" "<<
#define REP(i, a, b) for(ll i = a; i < b; i++)
#define dbg(x) cout << #x << " = " << x << endl
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define fast_io() ios_base::sync_with_stdio(false); cin.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())

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);
    }
};

template <typename Key, typename Value>
using hash_map = unordered_map<Key, Value, custom_hash>;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// uniform_int_distribution<int>(a, b)(rng);
// shuffle(all(a), rng);

ll max_weights(int n, int m, vector<int> x, vector<int> y, vector<int> w) {
    // this will contain at most O(n? + m)
    // time complexity O(n + m log m)
    vector<vector<pair<ll, ll>>> fish(n);
    map<ll, ll> total;
    REP(i, 0, m) {
        fish[x[i]].push_back({y[i], w[i]});
        total[x[i]] += w[i];
    }

    REP(i, 0, n) {
        sort(all(fish[i]));
    }

    vector<pair<ll, ll>> prev1, prev2, curr;
    prev1.push_back({-1, 0}), prev2.push_back({-1, 0});
    REP(i, 0, n) {
        // cerr << "i:" sp i sp "here" << endl;

        // gap
        ll mx = 0;
        for (auto &v : prev1) {
            mx = max(mx, v.second);
        }

        // adjacent
        vector<ll> pref;
        if (prev2.size()) pref.push_back(prev2[0].second);
        REP(j, 1, prev2.size()) {
            pref.push_back(pref.back() + prev2[j].second);
        }

        // self
        ll cnt = 0;
        for (auto &v : fish[i]) {
            cnt += v.second;

            ll cand = 0;
            auto it = lower_bound(curr.begin(), curr.end(), make_pair(v.first, -1LL));
            if (it != curr.end() and it->first == v.first) {
                cand = max(cand, it->second);
                curr.erase(it);
            }

            // gap
            cand = max(cand, mx + cnt);

            // adj
            int amt = i > 0 ? lower_bound(fish[i-1].begin(), fish[i-1].end(), make_pair(v.first, INF)) - fish[i-1].begin() : -1;
            ll add = (pref.size() and amt > 0) ? pref[amt-1] : 0;
            cand = max(cand, add + total[i] - cnt);

            curr.push_back({v.first, cand});
        }

        if (i > 0) {
            curr.push_back({n, total[i-1]});
        }

        prev1.swap(prev2);
        prev2.swap(curr);
        curr.clear();

    }

    ll ans = -1;
    for (auto &v : prev2) {
        ans = max(ans, v.second);
    }

    return ans;
}

// signed main() {
//     int n, m; cin >> n >> m;
//     vector<int> x(m), y(m), w(m);
//     REP(i, 0, m) {
//         cin >> x[i] >> y[i] >> w[i];
//     }

//     cout << max_weights(n, m, x, y, w) << endl;
// }

• Subtask 1: 0 / 3
• Subtask 2: 0 / 6
• Subtask 3: 0 / 9
• Subtask 4: 0 / 14
• Subtask 5: 0 / 21
• Subtask 6: 0 / 17
• Subtask 7: 0 / 14
• Subtask 8: 0 / 16