Submission #777880

#	Time	Username	Problem	Language	Result	Execution time	Memory
777880		t6twotwo	Swapping Cities (APIO20_swap)	C++17	37 / 100	2055 ms	8816 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
using namespace std;
int N;
vector<tuple<int, int, int>> edges;
constexpr int inf = 2e9;
void init(int n, int M, vector<int> U, vector<int> V, vector<int> W) {
    N = n;
    for (int i = 0; i < M; i++) {
        edges.emplace_back(W[i], U[i], V[i]);
    }
    sort(edges.begin(), edges.end());
}
int getMinimumFuelCapacity(int X, int Y) {
    vector<int> p(N);
    iota(p.begin(), p.end(), 0);
    function<int(int)> find = [&](int x) {
        return x == p[x] ? x : p[x] = find(p[x]);
    };
    vector<int> sz(N, 1), t(N), deg(N);
    auto unite = [&](int x, int y) {
        x = find(x);
        y = find(y);
        if (x == y) {
            t[x] = 1;
            return;
        }
        if (sz[x] > sz[y]) {
            swap(x, y);
        }
        p[x] = y;
        t[y] |= t[x];
        sz[y] += sz[x];
    };
    for (auto [z, x, y] : edges) {
        if (++deg[x] == 3) {
            t[find(x)] = 1;
        }
        if (++deg[y] == 3) {
            t[find(y)] = 1;
        }
        unite(x, y);
        if (find(X) == find(Y)) {
            if (t[p[X]]) {
                return z;
            }
        }
    }
    return -1;
}

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