Submission #562249

#	Time	Username	Problem	Language	Result	Execution time	Memory
562249		hollwo_pelw	Swapping Cities (APIO20_swap)	C++17	0 / 100	187 ms	39316 KiB

swap

#include "swap.h"

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

const int N = 1e5 + 5, M = 2e5 + 5;

int n, m, fa[N + M], val[N + M], col[N + M];
int par[19][N + M], nxt[N + M], d[N + M];
vector<int> adj[N + M];

inline int find(int u) { return fa[u] == u ? u : fa[u] = find(fa[u]); }
inline void merge(int u, int v, int w) {
	if ((u = find(u)) == (v = find(v))) {
		if (!col[u]) {
			fa[u] = ++ n;
			adj[n].push_back(u);
			col[n] = 1, val[n] = w;
		}
		return ;
	}
	fa[u] = fa[v] = ++ n;
	adj[n].push_back(u);
	adj[n].push_back(v);
	col[n] = col[u] | col[v], val[n] = w;
}

void pre_dfs(int u, int f = 0) {
	if (col[u]) f = u;
	nxt[u] = f;

	for (int v : adj[u]) {

		d[v] = d[par[0][v] = u] + 1;
		for (int i = 1; i < 19; i++)
			par[i][v] = par[i - 1][par[i - 1][v]];

		pre_dfs(v, f);
	}
}

inline int lca(int u, int v) {
	if (d[u] > d[v]) swap(u, v);
	
	for (int i = 19; i --; )
		if ((d[v] - d[u]) >> i & 1)
			v = par[i][v];
	if (u == v) return u;
	
	for (int i = 19; i --; )
		if (par[i][u] != par[i][v]) {
			u = par[i][u];
			v = par[i][v];
		}
	return par[0][u];
}

void init(int _n, int _m, vector<int> U, vector<int> V, vector<int> W) {
	n = _n, m = _m;

	iota(fa, fa + N + M, 0);

	vector<int> ids(m);
	iota(ids.begin(), ids.end(), 0);
	sort(ids.begin(), ids.end(), [&](const int &i, const int &j){
		return W[i] < W[j];
	});

	for (int i : ids)
		merge(U[i] + 1, V[i] + 1, W[i]);

	val[0] = -1, pre_dfs(n);
}

int getMinimumFuelCapacity(int X, int Y) {
	return -1;
	return val[nxt[lca(X + 1, Y + 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