Submission #745340

#	Time	Username	Problem	Language	Result	Execution time	Memory
745340		Lobo	Swapping Cities (APIO20_swap)	C++17	0 / 100	2100 ms	21776 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
using namespace std;
#define fr first
#define sc second
#define mp make_pair
#define pb push_back
#define all(x) x.begin(),x.end()
const int maxn = 2e5+10;
const int lg = 20;

int n, m, gr[maxn], ds[maxn], dsz[maxn], mn[maxn];
vector<int> mn0[maxn];
vector<pair<int,pair<int,int>>> edgs;
vector<pair<int,int>> g[maxn];

int find(int u) {
    if(ds[u] == u) return u;
    return ds[u] = find(ds[u]);
}

void join(int u, int v, int id) {
    gr[u]++;
    gr[v]++;
    int mxgr = max(gr[u],gr[v]);

    u = find(u);
    v = find(v);

    if(u == v || mxgr >= 3 || mn[u] != -1 || mn[v] != -1) {
        if(mn0[u].size()) {
            for(auto x : mn0[u]) {
                mn[x] = id;
            }
            mn0[u].clear();
        }
        if(mn0[v].size()) {
            for(auto x : mn0[v]) {
                mn[x] = id;
            }
            mn0[v].clear();
        }
    }
    if(u == v) return;

    if(dsz[u] < dsz[v]) swap(u,v);

    for(auto x : mn0[v]) {
        mn0[u].pb(x);
    }

    dsz[u]+= dsz[v];
    ds[v] = u;
}


void init(int N, int M, vector<int> U, std::vector<int> V, std::vector<int> W) {
    n = N;
    m = M;

    for(auto i = 0; i < m; i++) {
        edgs.pb(mp(W[i],mp(U[i],V[i])));
    }

    sort(all(edgs));

    for(int i = 0; i < n; i++) {
        gr[i] = 0;
        mn[i] = -1;
        ds[i] = i;
        dsz[i] = 1;
        mn0[i].clear();
        mn0[i].pb(i);
    }

    for(int i = 0; i < m; i++) {
        int u = edgs[i].sc.fr;
        int v = edgs[i].sc.sc;
        // if(find(u) != find(v)) {
        //     g[u].pb(mp(v,i));
        //     g[v].pb(mp(u,i));
        // }
        join(u,v,i);
    }
    // dfs(0,0,-1);
}

int getMinimumFuelCapacity(int x, int y) {
    for(int i = 0; i < n; i++) {
        gr[i] = 0;
        mn[i] = -1;
        ds[i] = i;
        dsz[i] = 1;
        mn0[i].clear();
        mn0[i].pb(i);
    }

    for(int i = 0; i < m; i++) {
        int u = edgs[i].sc.fr;
        int v = edgs[i].sc.sc;
        join(u,v,i);
        if(find(u) == find(v) && mn[u] != -1 && mn[v] != -1) return edgs[i].fr;
    }
    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