Submission #899136

#	Time	Username	Problem	Language	Result	Execution time	Memory
899136		GrindMachine	City Mapping (NOI18_citymapping)	C++17	25 / 100	38 ms	8832 KiB

citymapping

#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

/*

refs:
edi

*/

const int MOD = 1e9 + 7;
const int N = 1e3 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "citymapping.h"

ll disq[N][N];

ll get_dis(ll u, ll v){
	if(u == v) return 0;
	if(u > v) swap(u,v);
	if(disq[u][v] != -1) return disq[u][v];
	return disq[u][v] = get_distance(u,v);
}

bool on_path(ll w, ll u, ll v){
	// does w lie on the path from u to v?
	return get_dis(u,w)+get_dis(w,v) == get_dis(u,v);
}

vector<ll> adj[N];
vector<bool> rem(N);
vector<ll> subsiz(N);
vector<ll> tin(N), tout(N);
ll timer = 1;

void dfs1(ll u, ll p){
	tin[u] = timer++;
	subsiz[u] = 1;
	trav(v,adj[u]){
		if(v == p or rem[v]) conts;
		dfs1(v,u);
		subsiz[u] += subsiz[v];
	}
	tout[u] = timer-1;
}

bool is_ances(ll u, ll v){
	// is u an ances of v?
	return tin[u] <= tin[v] and tout[u] >= tout[v];
}

void find_roads(int n, int q, int A[], int B[], int W[]) {
	memset(disq,-1,sizeof disq);

	vector<ll> dis(n+5);
	for(int i = 2; i <= n; ++i){
		dis[i] = get_dis(1,i);
	}

	vector<pll> order;
	rep1(i,n) order.pb({dis[i],i});

	sort(all(order));
	ll ptr = 0;

	rep1(i,n-1){
		ll u = order[i].ss;
		fill(all(rem),0);
		ll p = -1;

		while(true){
			vector<ll> active;

			rep(j,i){
				ll v = order[j].ss;
				if(rem[v]) conts;
				active.pb(v);
			}

			if(sz(active) == 1){
				p = active[0];
				break;
			}

			ll root = active[0];
			timer = 1;
			dfs1(root,-1);

			ll nodes = sz(active);
			ll want = nodes/2;
			pll closest = {inf2,inf2};

			trav(v,active){
				pll px = {abs(want-subsiz[v]),v};
				amin(closest,px);
			}

			ll sub_node = closest.ss;
			vector<ll> in_sub;

			trav(v,active){
				if(is_ances(sub_node,v)){
					in_sub.pb(v);					
				}
			}

			if(on_path(sub_node,root,u)){
				// in sub of sub_node
				trav(v,active){
					rem[v] = 1;
				}
				trav(v,in_sub){
					rem[v] = 0;
				}
			}	
			else{
				// not in sub of v
				trav(v,in_sub){
					rem[v] = 1;
				}
			}
		}

		A[ptr] = p;
		B[ptr] = u;
		W[ptr] = dis[u]-dis[p];
		ptr++;

		adj[p].pb(u), adj[u].pb(p);
	}
}

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 0 / 13
• Subtask 4: 0 / 19
• Subtask 5: 0 / 43