Submission #980891

#	Time	Username	Problem	Language	Result	Execution time	Memory
980891		Marcus	Swapping Cities (APIO20_swap)	C++17	37 / 100	2077 ms	13504 KiB

swap

#include <bits/stdc++.h>
using namespace std;
 
int n, m;
vector<tuple<int, int, int>> edge;
 
vector<int> link;
vector<int> volume;
vector<bool> swapable;
vector<int> degree;
 
int find(int x) {
    if (x == link[x]) return x;
    return link[x] = find(link[x]);
}
 
bool same(int a, int b) {
    return find(a) == find(b);
}
 
void unite(int a, int b) {
    a = find(a); b = find(b);
    if (volume[a] < volume[b]) swap(a, b);
	volume[a] += volume[b];
	swapable[a] = swapable[a] || swapable[b];
    link[b] = a;
}
 
bool cmp(tuple<int, int, int>& tul1, tuple<int, int, int>& tul2)
{
	return (get<2>(tul1) < get<2>(tul2));
}
 
void init(int n1, int m1, vector<int> v, vector<int> u, vector<int> w) {
	n = n1;
	m = m1;
	for (int i=0; i<m; i++)
	{
		edge.push_back({v[i], u[i], w[i]});
	}
	sort(edge.begin(), edge.end(), cmp);
	link.resize(n, 0);
	volume.resize(n, 0);
	swapable.resize(n, 0);
	degree.resize(n, 0);
}
 
int getMinimumFuelCapacity(int x, int y) {
	for (int i=0; i<n; i++)
	{
	    link[i]=i;
	    volume[i]=1;
	    swapable[i]=0;
	    degree[i]=0;
	}
	for (int i=0; i<n; i++) {
		link[i] = i;
		volume[i] = 1;
	}
	for (auto e: edge)
	{
		int u = get<0>(e);
		int v = get<1>(e);
		int w = get<2>(e);
		degree[u]++; degree[v]++;
	    if (same(u, v) || degree[u] >= 3 || degree[v] >= 3) 
		{
			swapable[find(u)] = true;
	        swapable[find(v)] = true;
		}
		unite(u, v);
		if (same(x, y) && swapable[find(x)]) {return w;}
	}
	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