Submission #1117046

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117046		epicci23	Roller Coaster Railroad (IOI16_railroad)	C++17	0 / 100	126 ms	23480 KiB

railroad

#include "bits/stdc++.h"
#include "railroad.h"
#define ll long long 
#define all(v) v.begin() , v.end()
#define sz(a) (ll)a.size()
using namespace std;

const ll INF = 1e18;

struct DSU{
  vector<ll> par,siz;
  DSU(ll _n){
  	par.assign(_n,0);
  	iota(all(par),0);
    siz.assign(_n,1);
  }
  ll find(ll a){
  	if(par[a]==a) return a;
  	return par[a]=find(par[a]);
  }
  void unite(ll a,ll b){
  	a = find(a) , b = find(b);
  	if(a == b) return;
  	if(siz[a] > siz[b]) swap(a, b);
  	siz[b] += siz[a];
  	par[a] = b;
  }
};



ll plan_roller_coaster(vector<int> _s, vector<int> _t){
  ll n = sz(_s);
  array<ll,2> ar[n + 5];
  for(ll i = 1; i <= n; i++) ar[i][0] = _s[i], ar[i][1] = _t[i];
  ar[0] = {INF,1LL};

  vector<ll> zip;
  for(ll i=0;i<=n;i++){
  	zip.push_back(ar[i][0]);
  	zip.push_back(ar[i][1]);
  }

  sort(all(zip));
  zip.erase(unique(all(zip)),zip.end());
  
  auto Get = [&](ll val) -> ll{
    ll it = lower_bound(all(zip),val) - zip.begin();
    return it;
  };

  ll m = sz(zip);
  vector<ll> art(m+5,0),eks(m+5,0);
  DSU dsu(m+5);

  for(ll i = 0; i <= n ; i++){
  	ll a = Get(ar[i][0]);
    art[a]++;
    ll b = Get(ar[i][1]);
    eks[b]++;
    dsu.unite(a,b);
  }
  
  ll pa=0,pb=0,ans=0;
  for(ll i=0;i<m;i++){
    pa += art[i];
    pb += eks[i];
    if(pa > pb) ans+=(pa-pb)*(zip[i+1]-zip[i]);
    if(pa != pb) dsu.unite(i,i+1);
  }

  vector<array<ll,3>> edges;
  for(ll i=0;i+1<m;i++){
  	if(dsu.find(i)!=dsu.find(i+1)) edges.push_back({zip[i+1]-zip[i],dsu.find(i),dsu.find(i+1)});
  }

  sort(all(edges));
  for(auto x:edges){
  	if(dsu.find(x[1])!=dsu.find(x[2])){
  	  ans += x[0];
  	  dsu.unite(x[1],x[2]);
  	}
  }

  return ans;
}


/*void _(){
  ll n; cin >> n;
  array<ll,2> ar[n+5];
  for(ll i=1;i<=n;i++) cin >> ar[i][0] >> ar[i][1];
  ar[0] = {INF,1};

  vector<ll> zip;
  for(ll i=0;i<=n;i++){
  	zip.push_back(ar[i][0]);
  	zip.push_back(ar[i][1]);
  }

  sort(all(zip));
  zip.erase(unique(all(zip)),zip.end());
  
  auto Get = [&](ll val){
    ll it = lower_bound(all(zip),val) - zip.begin();
    return it;
  };

  ll m = sz(zip);
  vector<ll> art(m+5,0),eks(m+5,0);
  DSU dsu(m+5);

  for(ll i = 0; i <= n ; i++){
  	ll a = Get(ar[i][0]);
    art[a]++;
    ll b = Get(ar[i][1]);
    eks[b]++;
    dsu.unite(a,b);
  }
  
  ll pa=0,pb=0,ans=0;
  for(ll i=0;i<m;i++){
    pa += art[i];
    pb += eks[i];
    if(pa > pb) ans+=(pa-pb)*(zip[i+1]-zip[i]);
    if(pa != pb) dsu.unite(i,i+1);
  }

  vector<array<ll,3>> edges;
  for(ll i=0;i+1<m;i++){
  	if(dsu.find(i)!=dsu.find(i+1)) edges.push_back({zip[i+1]-zip[i],i,i+1});
  }

  sort(all(edges));
  for(auto x:edges){
  	if(dsu.find(x[1])!=dsu.find(x[2])){
  	  ans += x[0];
  	  dsu.unite(x[1],x[2]);
  	}
  }

  cout << ans << '\n';
}

int32_t main(){
  cin.tie(0); ios::sync_with_stdio(0);
  ll tc=1;//cin >> tc;
  while(tc--) _();
  return 0;
}*/

• Subtask 1: 0 / 11
• Subtask 2: 0 / 23
• Subtask 3: 0 / 30
• Subtask 4: 0 / 36