Submission #367017

#	Time	Username	Problem	Language	Result	Execution time	Memory
367017		fishy15	Arranging Tickets (JOI17_arranging_tickets)	C++14	45 / 100	6049 ms	5228 KiB

arranging_tickets

#include <iostream>
#include <iomanip>
#include <fstream>
#include <vector>
#include <array>
#include <algorithm>
#include <utility>
#include <map>
#include <queue>
#include <set>
#include <cmath>
#include <cstdio>
#include <cstring>

#define ll long long
#define ld long double
#define eps 1e-8
#define MOD 1000000007

#define INF 0x3f3f3f3f
#define INFLL 0x3f3f3f3f3f3f3f3f

// change if necessary
#define MAXN 200010

using namespace std;

int n, m;
vector<array<int, 3>> range[MAXN];
ll init[MAXN];
int min_check, max_check;

struct cmp {
    bool operator()(const array<int, 3> &a, const array<int, 3> &b) const {
        if (a[1] == b[1]) {
            if (a[0] == b[0]) {
                return a[2] < b[2];
            }
            return a[0] > b[0];
        }
        return a[1] < b[1];
    }
};

struct bit {
    ll vals[MAXN];
    void reset() {
        for (int i = 0; i < n + 10; i++) {
            vals[i] = 0;
        }
        for (int i = 0; i < n; i++) {
            ll x = init[i];
            if (i) x -= init[i - 1];
            upd(i, x);
        }
    }
    void upd(int x, ll v) {
        x++;
        while (x < n + 10) {
            vals[x] += v;
            x += x & -x;
        }
    }
    void upd(int l, int r, ll v) {
        upd(l, v);
        upd(r, -v);
    }
    ll qry(int x) {
        x++;
        ll res = 0;
        while (x) {
            res += vals[x];
            x -= x & -x;
        }
        return res;
    }
} b;

ll check(ll m, ll n, ll t) {
    b.reset();
    priority_queue<array<int, 3>, vector<array<int, 3>>, cmp> pq;
    for (int i = 0; i <= t; i++) {
        ll need_rem = max((b.qry(i) + n - m + 1) / 2, 0LL);
        n -= need_rem;
        for (auto &arr : range[i]) {
            if (arr[1] > t) {
                pq.push(arr);
            }
        }
        while (need_rem) {
            if (pq.empty()) {
                return false;
            }
            auto t = pq.top(); pq.pop();
            ll to_rem = min<ll>(t[2], need_rem);
            b.upd(0, t[0], to_rem);
            b.upd(t[0], t[1], -to_rem);
            b.upd(t[1], ::n, to_rem);
            t[2] -= to_rem;
            need_rem -= to_rem;
            if (t[2]) pq.push(t);
        }
    }

    for (int i = 0; i < ::n; i++) {
        if (b.qry(i) > m) {
            return false;
        }
    }

    return true;
}

ll check(ll m) {
    ll a = init[min_check];
    for (int i = 0; i <= ::m; i++) {
        for (int j = 0; j < n; j++) {
            if (check(m, i, j)) {
                return true;
            }
        }
    }

    return false;
    /* return check(m, a - m, min_check) || check(m, a - m + 1, min_check) */
        /* || check(m, a - m, max_check) || check(m, a - m + 1, max_check); */
}

int main() {
    cin.tie(0)->sync_with_stdio(0);

    cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int a, b, c; cin >> a >> b >> c;
        a--; b--;
        if (a > b) swap(a, b);
        init[a] += c;
        init[b] -= c;
        range[a].push_back({a, b, c});
    }

    for (int i = 1; i < n; i++) {
        init[i] += init[i - 1];
    }

    for (int i = 0; i < n; i++) {
        if (init[i] > init[min_check]) {
            min_check = i;
            max_check = i;
        } else if (init[i] == init[min_check]) {
            max_check = i;
        }
    }

    ll l = 0;
    ll r = init[min_check];
    ll ans = init[min_check];

    while (l <= r) {
        ll m = (l + r) / 2;
        if (check(m)) {
            ans = m;
            r = m - 1;
        } else {
            l = m + 1;
        }
    }

    cout << ans << '\n';

    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 35 / 35
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 15