Submission #395278

#	Time	Username	Problem	Language	Result	Execution time	Memory
395278		abc864197532	Swapping Cities (APIO20_swap)	C++17	0 / 100	2090 ms	16336 KiB

swap

#include <bits/stdc++.h>
// #include "grader_swap.cpp"
using namespace std;
#define lli long long int
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define test(x) cout << "Line(" << __LINE__ << ") " #x << ' ' << x << endl
#define printv(x) {\
	for (auto i : x) cout << i << ' ';\
	cout << endl;\
}
#define pii pair <int, int>
#define pll pair <lli, lli>
#define X first
#define Y second
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
template<typename A, typename B>
ostream& operator << (ostream& o, pair<A, B> a){
    return o << a.X << ' ' << a.Y;
}
template<typename A, typename B>
istream& operator >> (istream& o, pair<A, B> &a){
    return o >> a.X >> a.Y;
}
const int mod = 1e9 + 7, abc = 864197532, Doludu = 123, N = 100001, logN = 18, K = 40;

vector <pii> adj[N], out_of_tree[N];
int n, m;
vector <int> dsu;

int Find(int v) {
    if (dsu[v] == v) return v;
    return dsu[v] = Find(dsu[v]);
}

bool Union(int u, int v) {
    u = Find(u), v = Find(v);
    if (u == v) return false;
    dsu[u] = v;
    return true;
}

void init(int _n, int _m, vector <int> u, vector <int> v, vector <int> w) {
    n = _n, m = _m;
    dsu.resize(n);
    iota(all(dsu), 0);
    vector <int> p(m);
    iota(all(p), 0);
    sort(all(p), [&](int i, int j) {
        return w[i] < w[j];
    });
    for (int i : p) {
        if (Union(u[i], v[i])) {
            adj[u[i]].eb(v[i], w[i]);
            adj[v[i]].eb(u[i], w[i]);
        } else {
            out_of_tree[u[i]].eb(v[i], w[i]);
            out_of_tree[v[i]].eb(u[i], w[i]);
        }
    }
    for (int i = 0; i < n; ++i) {
        sort(all(out_of_tree[i]), [](pii i, pii j) {
            return i.Y < j.Y;
        });
    }
}

vector <int> road, W;
bool vis[N];

bool dfs(int v, int goal) {
    road.pb(v);
    vis[v] = true;
    if (v == goal) return true;
    for (auto [u, w] : adj[v]) if (!vis[u]) {
        W.pb(w);
        if (dfs(u, goal)) return true;
        W.pop_back();
    }
    road.pop_back();
    return false;
}

int getMinimumFuelCapacity(int u, int v) {
    road.clear();
    W.clear();
    for (int i = 0; i < n; ++i) vis[i] = false;
    dfs(u, v);
    int ans = 1 << 30;
    for (int i = 1; i < road.size() - 1; ++i) {
        for (auto [u, w] : adj[road[i]]) if (road[i - 1] != u && road[i + 1] != u) {
            ans = min(ans, w);
        }
        for (auto [u, w] : out_of_tree[road[i]]) {
            ans = min(ans, w);
        }
    }
    vector <int> tmp;
    for (auto [i, w] : adj[u]) if (i != road[1]) {
        tmp.pb(w);
    }
    for (auto [i, w] : out_of_tree[u]) {
        tmp.pb(w);
    }
    for (auto [i, w] : adj[v]) if (i != road[road.size() - 2]) {
        tmp.pb(w);
    }
    for (auto [i, w] : out_of_tree[v]) {
        tmp.pb(w);
    }
    sort(all(tmp));
    if (tmp.size() >= 2) ans = min(ans, tmp[1]);
    ans = max(ans, *max_element(all(W)));
    if (ans == 1 << 30) ans = -1;
    return ans;
}
/*
5 6
0 1 4
0 2 4
1 2 1
1 3 2
2 3 3
1 4 10
3
1 2
2 4
0 1

3 2
0 1 5
0 2 5
1
1 2
 */

Compilation message (stderr)

swap.cpp: In function 'int getMinimumFuelCapacity(int, int)':
swap.cpp:92:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |     for (int i = 1; i < road.size() - 1; ++i) {
      |                     ~~^~~~~~~~~~~~~~~~~

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