| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1042680 | Ausp3x | Parachute rings (IOI12_rings) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
// 人外有人，天外有天
// author: Ausp3x
#pragma GCC optimize("O1, O2, O3, Ofast, unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp
using namespace std;
using namespace __gnu_pbds;
#define fi first
#define se second
#define pb push_back
// #define DEBUG
typedef long long lng;
int const INF32 = 0x3f3f3f3f;
lng const INF64 = 0x3f3f3f3f3f3f3f3f;
struct UnionFind {
int n;
vector<int> link, node_size, edge_size;
UnionFind(int n): n(n) {
link.resize(n + 1);
iota(link.begin(), link.end(), 0);
node_size.resize(n + 1, 1);
edge_size.resize(n + 1);
}
int findSet(int v) {
if (v == link[v]) {
return link[v];
}
return link[v] = findSet(link[v]);
}
bool isSameSet(int a, int b) {
return findSet(a) == findSet(b);
}
void uniteSets(int a, int b) {
a = findSet(a);
b = findSet(b);
if (node_size[a] < node_size[b]) {
swap(a, b);
}
if (a == b) {
edge_size[a]++;
return;
}
node_size[a] += node_size[b];
edge_size[a] += edge_size[b];
link[b] = a;
return;
}
void debugPrint() {
cout << n << endl;
cout << "link:" << endl;
for (int x : link)
cout << x << ' ';
cout << endl;
cout << "node_size:" << endl;
for (int x : node_size)
cout << x << ' ';
cout << endl;
cout << "edge_size:" << endl;
for (int x : edge_size)
cout << x << ' ';
cout << endl;
return;
}
};
int N, E = 0;
vector<int> edg_cnts;
vector<vector<int>> adjl;
UnionFind uf(1000000);
void Init(int n) {
N = n;
edg_cnts.resize(n);
adjl.resize(n);
return;
}
void Link(int a, int b) {
edg_cnts[a]++;
edg_cnts[b]++;
adjl[a].pb(b);
adjl[b].pb(a);
E = max({E, edg_cnts[a], edg_cnts[b]});
uf.uniteSets(a, b);
return;
}
int CountCritical() {
if (E <= 2) {
map<int, int> cycle_sizes;
for (int i = 0; i < N; i++) {
int ii = uf.findSet(i);
if (uf.node_size[ii] == uf.edge_size[ii])
cycle_sizes[ii] = uf.node_size[ii];
}
if (cycle_sizes.size() == 0)
return N;
if (cycle_sizes.size() == 1)
return cycle_sizes[0];
return 0;
}
int greater_than_two_edges = 0;
for (int i = 0; i < N; i++)
if (edg_cnts[i] > 2)
greater_than_two_edges++;
for (int i = 0; i < N; i++) {
if (edg_cnts[i] > 2) {
int cur = 1;
for (int j : adjl[i])
if (edg_cnts[j] == 3)
cur++;
if (cur < greater_than_two_edges)
return 0;
if (cur == greater_than_two_edges)
return 1;
}
}
return -1;
}
#ifdef DEBUG
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
}
return 0;
}
#endif