Submission #102280

#	Time	Username	Problem	Language	Result	Execution time	Memory
102280		qkxwsm	Designated Cities (JOI19_designated_cities)	C++14	0 / 100	2097 ms	126912 KiB

designated_cities

#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

random_device(rd);
mt19937 rng(rd());
const long long FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();

struct custom_hash
{
	template<class T>
	unsigned long long operator()(T v) const
	{
		unsigned long long x = v;
		x += FIXED_RANDOM;
		// x += 11400714819323198485ull;
		// x = (x ^ (x >> 30)) * 13787848793156543929ull;
		x = (x ^ (x >> 27)) * 10723151780598845931ull;
		return x ^ (x >> 31);
	}
};

template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T, class U> using hash_table = gp_hash_table<T, U, custom_hash>;

template<class T>
T randomize(T mod)
{
	return (uniform_int_distribution<T>(0, mod - 1))(rng);
}
template<class T>
void readi(T &x)
{
	x = 0;
	bool negative = false;
	char c = ' ';
	while (c < '-')
	{
		c = getchar();
	}
	if (c == '-')
	{
		negative = true;
		c = getchar();
	}
	while (c >= '0')
	{
		x = x * 10 + (c - '0');
		c = getchar();
	}
	if (negative)
	{
		x = -x;
	}
}
template<class T>
void printi(T output)
{
	if (output == 0)
	{
		putchar('0');
		return;
	}
	if (output < 0)
	{
		putchar('-');
		output = -output;
	}
	int buf[20], n = 0;
	while(output)
	{
		buf[n] = ((output % 10));
		output /= 10;
		n++;
	}
	for (n--; n >= 0; n--)
	{
		putchar(buf[n] + '0');
	}
	return;
}
template<class T>
void ckmin(T &a, T b)
{
	a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
	a = max(a, b);
}
long long expo(long long a, long long e, long long mod)
{
	return ((e == 0) ? 1 : ((expo(a * a % mod, e >> 1, mod)) * ((e & 1) ? a : 1) % mod));
}
template<class T, class U>
void nmod(T &x, U mod)
{
	if (x >= mod) x -= mod;
}
template<class T>
T gcd(T a, T b)
{
	return (b ? gcd(b, a % b) : a);
}

#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define DBG(x) cerr << #x << " = " << (x) << endl
#define SZ(x) ((int) ((x).size()))
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define ALL(x) (x).begin(), (x).end()

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-9;

#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll
#define MAXN 200013

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
typedef vector<pdd> vpd;

int N, Q, R;
unordered_set<int> edge[MAXN];
hash_table<int, ll> dist[MAXN];
ll ans[MAXN];
ll tot;
int parent[MAXN], subtree[MAXN];
ll down[MAXN], up[MAXN];
ll enter[MAXN];
ll best[MAXN];
vl others[MAXN];
bitset<MAXN> done;

void dfs(int u)
{
	subtree[u] = 1;
	for (int v : edge[u])
	{
		if (v == parent[u] || done[v]) continue;
		parent[v] = u;
		dfs(v);
		subtree[u] += subtree[v];
	}
}
void dfs1(int u)
{
	for (int v : edge[u])
	{
		if (v == parent[u] || done[v]) continue;
		parent[v] = u;
		down[v] = down[u] + dist[u][v];
		up[v] = up[u] + dist[v][u];
		dfs(v);
		subtree[u] += subtree[v];
	}
}
void clean(int u)
{
	for (int v : edge[u])
	{
		if (v == parent[u] || done[v]) continue;
		clean(v);
	}
	subtree[u] = 0;
	parent[u] = N;
	others[u].clear();
	best[u] = 0;
	down[u] = 0;
	up[u] = 0;
}
int find_cent(int u, int sz)
{
	for (int v : edge[u])
	{
		if (v == parent[u] || done[v]) continue;
		if (subtree[v] * 2 > (sz / 2)) return find_cent(v, sz);
	}
	return u;
}
void solve(int u)
{
	bool flag = true;
	for (int v : edge[u])
	{
		if (v == parent[u] || done[v]) continue;
		flag = false;
		solve(v);
	}
	for (int v : edge[u])
	{
		if (v == parent[u] || done[v]) continue;
		if (SZ(others[v]) >= SZ(others[u]))
		{
			swap(others[v], others[u]);
		}
		others[u].insert(others[u].end(), ALL(others[v]));
		ll cur = best[u], could = best[v] + dist[u][v];
		if (cur) others[u].PB(min(cur, could));
		best[u] = max(cur, could);
	}
	return;
}
//now centroid decomp!
void go(int u)
{
	// DBG(u);
	dfs(u);
	ll mx1 = -LLINF, mx2 = -LLINF;
	for (int v : edge[u])
	{
		if (v == parent[u] || done[v]) continue;
		solve(v);
		ll cur = best[v] + dist[u][v];
		if (cur > mx1)
		{
			if (mx2 != -LLINF) others[u].PB(mx2);
			mx2 = mx1;
			mx1 = cur;
		}
		else if (cur > mx2)
		{
			if (mx2 != -LLINF) others[u].PB(mx2);
			mx2 = cur;
		}
		else
		{
			others[u].PB(cur);
		}
		others[u].insert(others[u].end(), ALL(others[v]));
	}
	sort(ALL(others[u]));
	ll sum = enter[u] - mx1 - mx2;
	ckmin(ans[2], sum);
	FOR(i, 3, 3 + SZ(others[u]))
	{
		sum -= others[u][SZ(others[u]) - i + 2];
		ckmin(ans[i], sum);
	}
	//now you always need to make sure you have stuff from multiple components!
	done[u] = true;
	clean(u);
	for (int v : edge[u])
	{
		if (done[v]) continue;
		edge[v].erase(u);
		dfs(v);
		if (subtree[v] == 1) continue;
		int c = find_cent(v, subtree[v]);
		clean(v);
		go(c);
	}
	return;
	//now just treat c as the root and yay!
}


int32_t main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	// cout << fixed << setprecision(10);
	// cerr << fixed << setprecision(10);
	// if (fopen("file.in", "r"))
	// {
	// 	freopen ("file.in", "r", stdin);
	// 	freopen ("file.out", "w", stdout);
	// }
	cin >> N;
	// N = 10000;
	FOR(i, 0, N - 1)
	{
		int u, v; ll c, d;
		cin >> u >> v >> c >> d;
		// u = i + 1; v = i + 2; c = randomize(INF); d = randomize(INF);
		u--; v--;
		dist[u][v] = c;
		dist[v][u] = d;
		tot += (c + d);
		edge[u].insert(v);
		edge[v].insert(u);
	}
	FOR(i, 0, N) if (SZ(edge[i]) != 1) R = i;
	parent[R] = N;
	dfs1(R);
	ll totdown = 0;
	FOR(i, 0, N) if (i != R) totdown += dist[parent[i]][i];
	FOR(u, 0, N) enter[u] = totdown + up[u] - down[u];
	FOR(i, 1, N + 1) ans[i] = LLINF;
	go(R);
	FOR(u, 0, N) ckmin(ans[1], enter[u]);
	FOR(i, 1, N) ckmin(ans[i + 1], ans[i]);
	cin >> Q;
	// Q = 0;
	while(Q--)
	{
		int x;
		cin >> x;
		if (N == 2)
		{
			cout << (x == 1 ? ans[x] : 0) << '\n';
			continue;
		}
		cout << ans[x] << '\n';
	}
	// cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}
/* READ READ READ
* int overflow, maxn too small, special cases (n=1?, two distinct?), cin.tie() interactive
* reread the problem, try small cases
* note down possible sources of error as you go
* do smth instead of nothing
*/

Compilation message (stderr)

designated_cities.cpp: In function 'void solve(int)':
designated_cities.cpp:213:7: warning: variable 'flag' set but not used [-Wunused-but-set-variable]
  bool flag = true;
       ^~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 7
• Subtask 3: 0 / 9
• Subtask 4: 0 / 17
• Subtask 5: 0 / 17
• Subtask 6: 0 / 44