제출 #319371

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
319371		VROOM_VARUN	Roller Coaster Railroad (IOI16_railroad)	C++14	100 / 100	626 ms	54824 KiB

railroad

/*
ID: varunra2
LANG: C++
TASK: railroad
*/

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

#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
  cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif

#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e9
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second

const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for(auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions

struct dsu{
  VI par;
  VI siz;

  void init(int n) {
    siz.assign(n, 1);
    par.resize(n);
    iota(all(par), 0);
  }
  
  int find(int x) {
    while(par[x] != par[par[x]]) par[x] = par[par[x]];
    return par[x];
  }

  bool merge(int x, int y) {
    x = find(x);
    y = find(y);
    if(x == y) return false;
    if(siz[x] < siz[y]) swap(x, y);
    siz[x] += siz[y];
    par[y] = x;
    return true;
  }
};

ll plan_roller_coaster(VI s, VI t) {
  s.PB(INF);
  t.PB(1);
  int n = sz(s);
  dsu dsu1;
  dsu1.init(n);
  VVI events;
  VVI edgs;
  for(int i = 0; i < n; i++) {
    events.PB({s[i], 1, i});
    events.PB({t[i], -1, i});
  }
  sort(all(events));
  ll ret = 0;
  ll tot = 0;
  for(int i = 0; i < sz(events) - 1; i++) {
    tot += events[i][1];
    ll dist = events[i + 1][0] - events[i][0];
    ret += dist * max(tot, 0ll);
    edgs.PB({(int)dist, events[i][2], events[i + 1][2]});
    if(dist == 0 or tot != 0) {
      dsu1.merge(events[i][2], events[i + 1][2]);
    }
  }
  sort(all(edgs));
  for(auto& x: edgs) {
    if(dsu1.merge(x[1], x[2])) ret += x[0];
  }
  return ret;
}

// int main() {
// #ifndef ONLINE_JUDGE
//   freopen("railroad.in", "r", stdin);
//   freopen("railroad.out", "w", stdout);
// #endif
//   cin.sync_with_stdio(0); cin.tie(0);

//   return 0;
// }

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