Submission #1093671

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093671		jonghak9028	Telegraph (JOI16_telegraph)	C++17	0 / 100	2 ms	2716 KiB

telegraph

/* ************************************************************************** */
/*                                                                            */
/*                                                      :::    :::    :::     */
/*   Problem Number: 17712                             :+:    :+:      :+:    */
/*                                                    +:+    +:+        +:+   */
/*   By: js9028 <boj.kr/u/js9028>                    +#+    +#+          +#+  */
/*                                                  +#+      +#+        +#+   */
/*   https://boj.kr/17712                          #+#        #+#      #+#    */
/*   Solved: 2024/09/27 11:02:15 by js9028        ###          ###   ##.kr    */
/*                                                                            */
/* ************************************************************************** */
#include <bits/stdc++.h>
using namespace std;
#define fastio (ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL))
typedef long long ll;
typedef long double lld;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
const int MAXSIZE = 2000000;
const long long INF = 1e18 + 5;
const double EPSILON = 1e-14;
const ll DIV = 2000003;
const long double pi = 3.14159265358979323846264338327950288419716939937510L;

int n;
pll adj[101010];
vector<pll> radj[101010];

ll mx[101010], sum[101010];
ll ans;

vector<int> cycle;
int vst[101010];
bool iscycle[101010];
ll cycle_sum;
ll cycle_val[101010];

int nt = 1;
int get_cycle(int cur)
{
    vst[cur] = nt;
    int ret = 0;
    auto nxt = adj[cur];

    if (vst[nxt.first] == nt)
    {
        iscycle[cur] = 1;
        cycle.push_back(cur);
        cycle_sum += adj[cur].second;
        cycle_val[nxt.first] = nxt.second;
        return nxt.first;
    }
    else if (vst[nxt.first])
        return 0;
    ret = max(ret, get_cycle(nxt.first));

    if (ret)
    {
        cycle_sum += adj[cur].second;
        cycle_val[nxt.first] = nxt.second;
        iscycle[cur] = 1;
        cycle.push_back(cur);
        if (ret == cur)
            return 0;
        return ret;
    }

    return ret;
}

int main()
{
    fastio;
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        ll a, b;
        cin >> a >> b;
        adj[i] = {a, b};
        radj[a].push_back({i, b});
        mx[a] = max(mx[a], b);
        sum[a] += b;
    }
    for (int i = 1; i <= n; i++)
    {
        if (vst[i])
            continue;
        cycle_sum = 0;
        cycle.clear();

        get_cycle(i);
        nt++;

        if (cycle.size() == n)
            break;
        if (cycle.empty())
            continue;
        ll tm = INF;
        ll psm = -cycle_sum;
        for (int j : cycle)
        {
            psm += sum[j];
            ll tx = 0;
            for (auto nx : radj[j])
            {
                if (iscycle[nx.first] == 0)
                {
                    tx = max(tx, nx.second);
                }
            }
            tm = min(tm, -tx + cycle_val[j]);
        }
        psm += tm;
        ans += psm;
    }

    for (int i = 1; i <= n; i++)
    {
        if (iscycle[i])
            continue;
        ans += sum[i] - mx[i];
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

telegraph.cpp: In function 'int main()':
telegraph.cpp:94:26: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   94 |         if (cycle.size() == n)
      |             ~~~~~~~~~~~~~^~~~

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