Submission #1224720

#	Time	Username	Problem	Language	Result	Execution time	Memory
1224720		_rain_	Arranging Tickets (JOI17_arranging_tickets)	C++20	0 / 100	4 ms	5640 KiB

arranging_tickets

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

const int N = 200200;

int n, m, pos = 0;
long long a[N], s[N];
vector<pair<int, int>> upd[N];

bool check (long long take, long long lim){
    fill(s, s + n + 1, 0ll);
    priority_queue<pair<int, int>> pq;
    long long cur = 0;
    for (int i = 1; i <= pos; ++i){
        long long need = (a[i] + take - lim + 1) / 2ll;
        assert(need<=lim);
        for (auto [x, y] : upd[i]){
            if (x > pos){
                pq.push({x, y});
            }
        } 
        while (cur < need){
            if (pq.empty()){
                return false;
            }
            auto [x, y] = pq.top(); pq.pop();
            if (cur + 1ll * y <= need){
                cur += 1ll * y;
                s[x] += 1ll * y;
            } else {
                long long add = need - cur;
                cur += add;
                s[x] += add;
                y -= (int)(add);
                pq.push({x, y});
            }
        }
    }
    for (int i = pos + 1; i <= n; ++i){
        cur -= s[i];
        if (1ll * a[i] + take - 2ll * cur > lim){
            return false;
        }
    }
    return true;
}

int32_t main (){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    if (fopen ("main.inp", "r")){
        freopen ("main.inp", "r", stdin);
        freopen ("main.out", "w", stdout);
    }
    cin >> n >> m;
    for (int i = 1; i <= m; ++i){
        int x, y, z; cin >> x >> y >> z;
        if (x > y){
            swap(x, y);
        }
        a[x] += 1ll * z;
        a[y] -= 1ll * z;
        upd[x].push_back({y, z});
    }
    for (int i = 1; i <= n; ++i){
        a[i] += a[i - 1];
        if (a[pos] < a[i]){
            pos = i;
        }
    }
    long long l = 0, r = 1ll * m * (int)(1e9), ans = r;
    while (l <= r){
        long long mid = l + r >> 1;
        bool possible = (check(a[pos] - mid, mid) || check(a[pos] - mid + 1, mid));
        if (possible){
            ans = mid;
            r = mid - 1;
        } else {
            l = mid + 1;
        }
    }
    cout << ans << "\n";
}

Compilation message (stderr)

arranging_tickets.cpp: In function 'int32_t main()':
arranging_tickets.cpp:51:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         freopen ("main.inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
arranging_tickets.cpp:52:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen ("main.out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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