Submission #614054

#	Time	Username	Problem	Language	Result	Execution time	Memory
614054		IWTIM	Logičari (COCI21_logicari)	C++14	110 / 110	250 ms	41412 KiB

Main

# include <bits/stdc++.h>
using namespace std;
using ll = long long;
using db = long double; // or double, if TL is tight
using str = string; // yay python! 
 
// pairs
using pii = pair<int,int>;
using pl = pair<ll,ll>;
using pd = pair<db,db>;
#define mp make_pair
#define f first
#define s second
 
#define tcT template<class T
#define tcTU tcT, class U
// ^ lol this makes everything look weird but I'll try it
tcT> using V = vector<T>; 
tcT, size_t SZ> using AR = array<T,SZ>; 
using vi = V<int>;
using vb = V<bool>;
using vl = V<ll>;
using vd = V<db>;
using vs = V<str>;
using vpi = V<pii>;
using vpl = V<pl>;
using vpd = V<pd>;
 
// vectors
// oops size(x), rbegin(x), rend(x) need C++17
#define sz(x) int((x).size())
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define rall(x) x.rbegin(), x.rend() 
#define sor(x) sort(all(x)) 
#define rsz resize
#define ins insert 
#define pb push_back
#define eb emplace_back
#define ft front()
#define bk back()
 
#define lb lower_bound
#define ub upper_bound
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define rep(a) F0R(_,a)
#define each(a,x) for (auto& a: x)
const int MOD = 998244353;
const int MX = 2e5+5;
const ll BIG = 1e18; // not too close to LLONG_MAX
const db PI = acos((db)-1);
const int dx[4]{1,0,-1,0}, dy[4]{0,1,0,-1}; // for every grid problem!!
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 
template<class T> using pqg = priority_queue<T,vector<T>,greater<T>>;
struct DSU {
	vi e; void init(int N) { e = vi(N,-1); }
	int get(int x) { return e[x] < 0 ? x : e[x] = get(e[x]); } 
	bool sameSet(int a, int b) { return get(a) == get(b); }
	int size(int x) { return -e[get(x)]; }
	bool unite(int x, int y) { // union by size
		x = get(x), y = get(y); if (x == y) return 0;
		if (e[x] > e[y]) swap(x,y);
		e[x] += e[y]; e[y] = x; return 1;
	}
};
/*
inline namespace Helpers {
	//////////// is_iterable
	// https://stackoverflow.com/questions/13830158/check-if-a-variable-type-is-iterable
	// this gets used only when we can call begin() and end() on that type
	tcT, class = void> struct is_iterable : false_type {};
	tcT> struct is_iterable<T, void_t<decltype(begin(declval<T>())),
	                                  decltype(end(declval<T>()))
	                                 >
	                       > : true_type {};
	tcT> constexpr bool is_iterable_v = is_iterable<T>::value;
 
	//////////// is_readable
	tcT, class = void> struct is_readable : false_type {};
	tcT> struct is_readable<T,
	        typename std::enable_if_t<
	            is_same_v<decltype(cin >> declval<T&>()), istream&>
	        >
	    > : true_type {};
	tcT> constexpr bool is_readable_v = is_readable<T>::value;
 
	//////////// is_printable
	// // https://nafe.es/posts/2020-02-29-is-printable/
	tcT, class = void> struct is_printable : false_type {};
	tcT> struct is_printable<T,
	        typename std::enable_if_t<
	            is_same_v<decltype(cout << declval<T>()), ostream&>
	        >
	    > : true_type {};
	tcT> constexpr bool is_printable_v = is_printable<T>::value;
}*/
#define f first
#define s second
#define pb push_back
#define int long long
const int N = 3e5 + 5, inf = 1e9;
int t,n,a[N],fix[N],par[N],root,special,b[N];
vector <int> v[N];
int dp[N][2][2][2][2];
void dfs(int a, int p) {
	fix[a] = 1;
	for (int i = 0; i < (int)v[a].size(); i++){
		int to = v[a][i];
		if (to == p) continue;
		if (fix[to]) {
			root = a;
			special = to;
		}
		else
		dfs(to,a);
	}
}
void dfs1(int a, int p) {
	par[a] = p;
	for (int i = 0; i < (int)v[a].size(); i++) {
		int to = v[a][i];
		if (to == p) continue;
		dfs1(to,a);
	}
}
void dfs2(int a, int p, int me, int up, int rt, int sp) {
	if (dp[a][me][up][rt][sp] != -1) return ;
	if ((a == special && me != sp) ||  (a == root && me != rt) || (p == root && up != rt) || (p == special && up != sp) || (a == special && up && rt)) {
		dp[a][me][up][rt][sp] = inf;
		return ;
	}
	int ff = 0;
	if (a != root) {
		if(up == 1) ff = 1;
		if (a == special && rt) ff = 1;
	}
	else if (sp) ff = 1;
	int dif = 1e9, sum = 0;
	for (int i = 0; i < (int)v[a].size(); i++) {
		int to = v[a][i];
		if (to == p) continue;
	 	dfs2(to,a,0,me,rt,sp);
		dfs2(to,a,1,me,rt,sp);
		sum += dp[to][0][me][rt][sp];
		dif = min(dif, dp[to][1][me][rt][sp] - dp[to][0][me][rt][sp]);
	}
	dp[a][me][up][rt][sp] = (ff == 1 ? sum + me : sum + dif + me);
}
main() {
    std::ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);
    cin>>n;
    for (int i = 1; i <= n; i++) {
    	cin>>a[i]>>b[i];
    	v[a[i]].pb(b[i]);
    	v[b[i]].pb(a[i]);
	}
	dfs(1,0);
	for (int i = 1; i <= n; i++) v[i].clear();
	for (int i = 1; i <= n; i++) {
		if (min(a[i],b[i]) == min(root,special) && max(a[i],b[i]) == max(root,special)) {}
		else v[a[i]].pb(b[i]), v[b[i]].pb(a[i]);
	}
	for (int i = 1; i <= n; i++) {
		for (int j = 0; j <= 1; j++) {
			for (int jj = 0; jj <= 1; jj++) {
				for (int ii = 0; ii <= 1; ii++) {
					dp[i][j][jj][ii][0] = dp[i][j][jj][ii][1] = -1;
				}
			}
		}
	}
	int ans = inf;
	dfs1(root,0);
	for (int rt = 0; rt <= 1; rt++) {
		for (int sp = 0; sp <= 1; sp++) {
			dfs2(root,0,rt,0,rt,sp);
			ans = min(ans,dp[root][rt][0][rt][sp]);
		}
	}
	cout<<(ans > n ? -1 : ans)<<endl;
}

Compilation message (stderr)

Main.cpp:152:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  152 | main() {
      | ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 40 / 40
• Subtask 4: 50 / 50