Submission #748061

#	Time	Username	Problem	Language	Result	Execution time	Memory
748061		onebit1024	City Mapping (NOI18_citymapping)	C++17	13 / 100	237 ms	748 KiB

citymapping

#include "citymapping.h"
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define pb push_back
#define all(c) c.begin(), c.end()
#define endl "\n"

const double PI=3.141592653589;


void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");} 

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define dbg(x...) cerr << "LINE(" << __LINE__ << ") -> " <<"[" << #x << "] = ["; _print(x)
#else
#define dbg(x...)
#endif

vector<int>sub,in,out;
vector<vector<int>>adj;
int t = 1;
void comp(int u, int p,set<int>&active){
	sub[u] = 1;
	in[u] = t++;
	for(int v : adj[u]){
		if(v==p || !active.count(v))continue;
		comp(v,u,active);
		sub[u]+=sub[v];
	}
	out[u] = t++;
}
bool above(int u, int v){
	return in[u] <= in[v] && out[u] >= out[v];
}
void find_roads(int n, int Q, int a[], int b[], int w[]) {
	vector<pair<ll,int>>k;
	vector<ll>dist1(n+1);
	for(int i = 2;i<=n;++i)dist1[i] = get_distance(1,i);
	for(int i = 2;i<=n;++i)k.pb({dist1[i],i});

	sort(all(k));
	adj.resize(n+1);
	sub.resize(n+1);
	in.resize(n+1);
	out.resize(n+1);
	set<int>active = {1};
	int p = 0;
	for(int i = 0;i<k.size();++i){
		int prev = 1,last = 0;
		while(active.size()>1){
			sub = vector<int>(n+1);
			in = vector<int>(n+1);
			out = vector<int>(n+1);
			t = 1;
			comp(prev,-1,active);
			int sz = active.size();
			int mn = 1e9, x = 1;
			for(auto w : active){
				if(abs((sz/2)-sub[w]) < mn){
					mn = abs((sz/2)-sub[w]);
					x = w;
				}
			}
			int u = k[i].second;
			set<int>ne;
			int kkk = get_distance(x,u);
			last = kkk;
			if(dist1[x]+kkk == dist1[u]){
				// all nodes in subtree of x are valid
				prev = x;
				for(auto y : active){
					if(above(x,y))ne.insert(y);
				}
			}else{
				// all nodes not in subtree of x are valid
				prev = 1;
				for(auto y : active){
					if(!above(x,y))ne.insert(y);
				}
			}
			active = ne;
		}
		int v = *active.begin();
		adj[k[i].second].pb(v);
		adj[v].pb(k[i].second);
		a[p] = k[i].second;
		b[p] = v;
		w[p++] = get_distance(k[i].second,v);
		for(int j = 0;j<=i;++j)active.insert(k[j].second);
		active.insert(1);
	}
	return;
}

Compilation message (stderr)

citymapping.cpp: In function 'void find_roads(int, int, int*, int*, int*)':
citymapping.cpp:68:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |  for(int i = 0;i<k.size();++i){
      |                ~^~~~~~~~~
citymapping.cpp:69:16: warning: variable 'last' set but not used [-Wunused-but-set-variable]
   69 |   int prev = 1,last = 0;
      |                ^~~~

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