Submission #1014214

#	Time	Username	Problem	Language	Result	Execution time	Memory
1014214		gmroh06	Telegraph (JOI16_telegraph)	C++17	0 / 100	0 ms	348 KiB

telegraph

#import <bits/stdc++.h>

using namespace std;
using ll = long long;

inline void init() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
}

int main() {
    init();

    ll n, ans = 0;

    cin >> n;

    vector<pair<ll, ll>> gr(n + 1);
    vector<ll> vst(n + 1), x(n + 1), y(n + 1);
    vector<bool> cycle(n + 1);

    for (ll i = 1; i <= n; i++) {
        cin >> gr[i].first >> gr[i].second;
        ans += gr[i].second;
    }

    for (ll i = 1, cnt = 0;; i = gr[i].first, vst[++cnt] = 1) {
        if (vst[i]) {
            if (i == 1 and cnt == n) {
                cout << 0;
                return 0;
            }
            break;
        }
    }

    fill(vst.begin(), vst.end(), 0);

    for (ll i = 1, tmp = 1; i <= n; tmp = ++i) {
        if (vst[i]) continue;

        while (!vst[tmp]) {
            vst[tmp] = i;
            tmp = gr[tmp].first;
        }

        if (vst[tmp] != i) continue;

        while (!cycle[tmp]) {
            cycle[tmp] = true;
            tmp = gr[tmp].first;
        }
    }

    for (ll i = 1; i <= n; i++) {
        x[gr[i].first] = max(x[gr[i].first], gr[i].second);
        if (!cycle[i]) y[gr[i].first] = max(y[gr[i].first], gr[i].second);
    }

    for (ll i = 1, mx, tmp = 1; i <= n; tmp = ++i) {
        ans -= x[i];

        if (!cycle[i]) continue;

        mx = -1e18;

        while (cycle[tmp]) {
            mx = max(mx, y[tmp] - x[tmp]);
            cycle[tmp] = false;
            tmp = gr[tmp].first;
        }

        ans -= mx;
    }

    cout << ans;

    return 0;
}

Compilation message (stderr)

telegraph.cpp:1:2: warning: #import is a deprecated GCC extension [-Wdeprecated]
    1 | #import <bits/stdc++.h>
      |  ^~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 30
• Subtask 3: 0 / 30
• Subtask 4: 0 / 30