Submission #1000289

#	Time	Username	Problem	Language	Result	Execution time	Memory
1000289		pan	Road Closures (APIO21_roads)	C++17	100 / 100	300 ms	54216 KiB

roads

#include <bits/stdc++.h>
//#include "bits_stdc++.h"
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define endl '\n'
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define input(x) scanf("%lld", &x);
#define input2(x, y) scanf("%lld%lld", &x, &y);
#define input3(x, y, z) scanf("%lld%lld%lld", &x, &y, &z);
#define input4(x, y, z, a) scanf("%lld%lld%lld%lld", &x, &y, &z, &a);
#define print(x, y) printf("%lld%c", x, y);
#define show(x) cerr << #x << " is " << x << endl;
#define show2(x,y) cerr << #x << " is " << x << " " << #y << " is " << y << endl;
#define show3(x,y,z) cerr << #x << " is " << x << " " << #y << " is " << y << " " << #z << " is " << z << endl;
#define all(x) x.begin(), x.end()
#define discretize(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
#define FOR(i, x, n) for (ll i =x; i<=n; ++i) 
#define RFOR(i, x, n) for (ll i =x; i>=n; --i) 
using namespace std;
mt19937_64 rnd(chrono::steady_clock::now().time_since_epoch().count());
//using namespace __gnu_pbds;
//#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
//#define ordered_multiset tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
typedef long long ll;
typedef long double ld;
typedef pair<ld, ll> pd;
typedef pair<string, ll> psl;
typedef pair<ll, ll> pi;
typedef pair<pi, ll> pii;
typedef pair<pi, pi> piii;

struct balancedheap
{
	multiset<ll> chosen, store;
	ll k, sum;
	balancedheap() {k =-1; sum = 0;}
	void balance()
	{
		if (k==-1) return;
		while (chosen.size() > k && chosen.size())
		{
			sum -= *prev(chosen.end());
			store.insert(*prev(chosen.end()));
			chosen.erase(prev(chosen.end()));
		}
		while (chosen.size() < k && store.size() && *store.begin() < 0)
		{
			sum += *store.begin();
			chosen.insert(*store.begin());
			store.erase(store.begin());
		}
		while (chosen.size() && store.size() && *prev(chosen.end()) > *store.begin())
		{
			ll x = *store.begin(), y = *prev(chosen.end());
			sum += x - y;
			store.erase(store.begin()); chosen.erase(--chosen.end());
			store.insert(y); chosen.insert(x);
		}
	}
	void insert(ll x)
	{
		store.insert(x);
		balance();
	}
	void erase(ll x)
	{
		if (chosen.find(x)==chosen.end()) {store.erase(store.lb(x));}
		else{sum -= x; chosen.erase(chosen.lb(x));}
		balance();
	}
	void setcap(ll x){k = x; balance();}
};

ll const MAXN = 100005;
ll n, k;
set<pi> adj[MAXN];
ll vis[MAXN], dp[MAXN][2], sum[MAXN], deg[MAXN];
balancedheap hp[MAXN];
vector<pi> order;
vector<ll> ans;

void dfs(ll x, ll p)
{
	vis[x] = 1;
	ll ans = sum[x];
	vector<ll> bt;
	for (pi u: adj[x]) 
	{
		if (u.f==p) continue;
		dfs(u.f, x);
		ans += dp[u.f][1] + u.s;
		ll ch = dp[u.f][0] - dp[u.f][1] -  u.s;
		hp[x].insert(ch);
		bt.pb(ch);
	}
	hp[x].setcap(k-1);
	dp[x][0] = ans +hp[x].sum;
	hp[x].setcap(k);
	dp[x][1] = ans + hp[x].sum;
	for (ll u: bt) hp[x].erase(u);
}

std::vector<long long> minimum_closure_costs(int N, std::vector<int> U, std::vector<int> V, std::vector<int> W)
{
	n = N;
	for (ll i=0; i<n; ++i) {sum[i] = deg[i] = 0;}
	for (ll i=0; i<n-1; ++i)
	{
		adj[U[i]].insert(mp(V[i], W[i]));
		adj[V[i]].insert(mp(U[i], W[i]));
		deg[U[i]]++; deg[V[i]]++;
	}
	for (ll i=0; i<n; ++i) {order.pb(mp(deg[i], i)); vis[i] = 0;}
	sort(all(order));
	ll idx = 0;
	ans.assign(n, 0);
	//show(1);
	for (ll j=0; j<n; ++j)
	{
		k = j;
		ans[j] = 0;
		while (idx < n && order[idx].f <= k)
		{
			ll now = order[idx].s;
			for (pi u: adj[now])
			{
				sum[u.f] += u.s;
				hp[u.f].insert(-u.s);
				adj[u.f].erase(mp(now, u.s));
			}
			idx++;
		}
		for (ll i=idx; i<n; ++i) vis[order[i].s]= 0;
		for (ll i=idx; i<n; ++i)  if (!vis[order[i].s]) 
		{
			dfs(order[i].s, -1);
			ans[j] += dp[order[i].s][1];
		}
	}
	return ans;
	
	
	
}
                                        

Compilation message (stderr)

roads.cpp: In member function 'void balancedheap::balance()':
roads.cpp:45:24: warning: comparison of integer expressions of different signedness: 'std::multiset<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   45 |   while (chosen.size() > k && chosen.size())
      |          ~~~~~~~~~~~~~~^~~
roads.cpp:51:24: warning: comparison of integer expressions of different signedness: 'std::multiset<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   51 |   while (chosen.size() < k && store.size() && *store.begin() < 0)
      |          ~~~~~~~~~~~~~~^~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 14 / 14
• Subtask 4: 10 / 10
• Subtask 5: 17 / 17
• Subtask 6: 25 / 25
• Subtask 7: 22 / 22