Submission #1233367

#	Time	Username	Problem	Language	Result	Execution time	Memory
1233367		badge881	Swapping Cities (APIO20_swap)	C++20	0 / 100	0 ms	320 KiB

swap

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

const int MN = 2e5 + 5;
const int INF = 1e9 + 10;
int n, m;
int par[MN], sz[MN], large[MN];
vector<tuple<int, int, int>> edges; // <u, v, w>
vector<vector<int>> g;
vector<int> deg, maxDeg;
vector<bool> av, inPath, vis, cyc;

int boss(int u)
{
    if (par[u] == u)
        return u;
    return par[u] = boss(par[u]);
}

void merge(int e)
{
    auto [u, v, w] = edges[e];
    deg[u]++, deg[v]++;
    maxDeg[boss(u)] = max(maxDeg[boss(u)], deg[u]);
    maxDeg[boss(v)] = max(maxDeg[boss(v)], deg[v]);
    u = boss(u), v = boss(v);
    if (u == v)
    {
        cyc[u] = true;
        return;
    }
    if (sz[u] > sz[v])
        swap(u, v);
    par[u] = v;
    sz[v] += sz[u];
    maxDeg[v] = max(maxDeg[v], maxDeg[u]);
    cyc[v] = cyc[u] || cyc[v];
}

void init(int N, int M, vector<int> U, vector<int> V, vector<int> W)
{
    n = N, m = M;
    for (int i = 0; i < m; i++)
    {
        edges.push_back({W[i], U[i], V[i]});
    }
    sort(edges.begin(), edges.end());
    g.resize(n);
    for (int i = 0; i < m; i++)
    {
        auto [u,v,w] = edges[i];
        g[u].push_back(i);
        g[v].push_back(i);
    }
}

int getMinimumFuelCapacity(int X, int Y)
{
    int a = X, b = Y;
    deg.assign(n, 0);
    maxDeg.assign(n, 0);
    cyc.assign(n, 0);
    for (int i = 0; i < n; i++)
        par[i] = i,
        sz[i] = 1;

    for (int i = 0; i < m; i++)
    {
        merge(i);
        if (boss(a) == boss(b) && (maxDeg[boss(a)] >= 3 || cyc[boss(a)]))
            return get<0>(edges[i]);
    }
    return -1;
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 7
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27