| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 786308 | ono_de206 | 수천개의 섬 (IOI22_islands) | 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.
#include "islands.h"
#include<bits/stdc++.h>
using namespace std;
#define in insert
#define all(x) x.begin(),x.end()
#define pb push_back
#define eb emplace_back
#define ff first
#define ss second
//#define int long long
typedef long long ll;
typedef vector<int> vi;
typedef set<int> si;
typedef multiset<int> msi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
const int mxn = 1e5 + 10;
vector<pair<int, int>> g[mxn];
bool tp, found;
vector<int> ans;
int vis[mxn], p[mxn];
void dfs(int to, int fr) {
p[to] = fr;
vis[to] = 1;
vector<int> lol;
for(auto it : g[to]) {
int x = it.ff, id = it.ss;
if(id == fr || vis[x]) continue;
lol.pb(id);
}
if(lol.size() >= 2 && !tp) {
vector<int> tmp = ans;
tmp.pb(lol[0]);
tmp.pb(lol[0] ^ 1);
tmp.pb(lol[1]);
tmp.pb(lol[1] ^ 1);
tmp.pb(lol[0] ^ 1);
tmp.pb(lol[0]);
tmp.pb(lol[1] ^ 1);
tmp.pb(lol[1]);
tmp.in(tmp.end(), ans.rbegin(), ans.end());
swap(tmp, ans);
found = 1;
return;
}
if(found) return;
for(auto it : g[to]) {
int x = it.ff, id = it.ss;
if(vis[x] == 2) continue;
if(id / 2 == fr / 2) continue;
ans.pb(id);
if(vis[x] == 1) {
found = 1;
vector<int> cyc;
while(ans.size() && ans.back() != p[x]) {
cyc.pb(ans.back());
ans.pop_back();
}
reverse(all(cyc));
vector<int> tmp = ans;
if(tp) {
for(int x : cyc) tmp.pb(x);
for(int x : cyc) tmp.pb(x ^ 1);
reverse(all(cyc));
for(int x : cyc) tmp.pb(x);
for(int x : cyc) tmp.pb(x ^ 1);
} else {
for(int x : cyc) tmp.pb(x);
reverse(all(cyc));
for(int x : cyc) tmp.pb(x ^ 1);
for(int x : cyc) tmp.pb(x);
reverse(all(cyc));
for(int x : cyc) tmp.pb(x ^ 1);
}
tmp.in(tmp.end(), ans.rbegin(), ans.rend());
swap(tmp, ans);
} else {
dfs(x, id);
}
if(found) return;
ans.pop_back();
}
vis[to] = 2;
}
variant<bool, vector<int>> find_journey(int n, int m, vector<int> U, vector<int> V) {
if(n == 2) {
vector<int> a0, a1;
for(int i = 0; i < m; i++) {
if(U[i] == 0) a0.pb(i);
else a1.pb(i);
}
if(a0.size() >= 2 && a1.size() >= 1) return vector<int>{a0[0], a1[0], a0[1], a0[0], a1[0], a0[1]};
else return false;
}
if(U[0] == U[1]) tp = 1;
for(int i = 0; i < m; i++) {
g[U[i]].eb(V[i], i);
}
dfs(0, -10000);
if(found) return ans;
return false;
}