#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a,b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a,b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
/*
*/
const int MOD = 1e9 + 7;
const int N = 500 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
#include "simurgh.h"
vector<pii> adj[N];
vector<bool> vis(N);
vector<int> tin(N), tout(N), low(N);
vector<int> back_edges(N);
vector<pii> par(N);
int timer;
void dfs1(int u, int p){
vis[u] = 1;
tin[u] = low[u] = timer++;
for(auto [v,id] : adj[u]){
if(v == p) conts;
if(vis[v]){
if(tin[u] > tin[v]){
back_edges[u]++;
}
amin(low[u],tin[v]);
}
else{
par[v] = {u,id};
dfs1(v,u);
amin(low[u],low[v]);
}
}
tout[u] = timer++;
}
std::vector<int> find_roads(int n, std::vector<int> U, std::vector<int> V) {
vector<array<int,3>> edges;
rep(i,sz(U)){
int u = U[i], v = V[i];
edges.pb({u,v,i});
}
auto in_sub = [&](int u, int v){
// is u in the sub of v?
return tin[u] >= tin[v] and tout[u] <= tout[v];
};
while(sz(edges) >= n){
rep(i,n){
adj[i].clear();
vis[i] = 0;
back_edges[i] = 0;
}
timer = 0;
for(auto [u,v,id] : edges){
adj[u].pb({v,id}), adj[v].pb({u,id});
}
dfs1(0,-1);
vector<bool> good(sz(U));
vector<int> spanning;
rep1(i,n-1){
spanning.pb(par[i].ss);
good[par[i].ss] = 1;
}
rep(i,n){
if(!back_edges[i]) conts;
auto [p,pid] = par[i];
spanning.erase(find(all(spanning),pid));
spanning.pb(pid);
vector<array<int,3>> consider;
vector<array<int,3>> edges2;
for(auto [u,v,id] : edges){
if(good[id]){
if(id != pid){
edges2.pb({u,v,id});
}
conts;
}
// does this edge cross through i?
// 1 node in sub of u, other outside sub of u (wlog, depth(u) > depth(v))
if(tin[u] < tin[v]) swap(u,v);
if(in_sub(u,i) and !in_sub(v,i)){
consider.pb({u,v,id});
}
else{
edges2.pb({u,v,id});
}
}
int original = count_common_roads(spanning);
bool spanning_ok = true;
for(auto [u,v,id] : consider){
spanning.pop_back();
spanning.pb(id);
int curr = count_common_roads(spanning);
if(curr > original){
spanning_ok = false;
edges2.pb({u,v,id});
}
spanning.pop_back();
spanning.pb(pid);
}
if(spanning_ok){
edges2.pb({i,p,pid});
}
edges = edges2;
break;
}
}
vector<int> ans;
for(auto [u,v,id] : edges){
ans.pb(id);
}
return ans;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
WA in grader: NO |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
WA in grader: NO |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
WA in grader: NO |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
0 ms |
456 KB |
correct |
| 2 |
Incorrect |
0 ms |
348 KB |
WA in grader: NO |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
WA in grader: NO |
| 2 |
Halted |
0 ms |
0 KB |
- |
