Submission #557433

#	Time	Username	Problem	Language	Result	Execution time	Memory
557433		600Mihnea	Road Construction (JOI21_road_construction)	C++17	0 / 100	1 ms	212 KiB

road_construction

#include <bits/stdc++.h>

bool home = 1;

using namespace std;

typedef long long ll;
const int N=250000+7;

struct T{
  ll x;
  ll y;
};

bool cmpTx(T a,T b) {
  return a.x<b.x;
}

int n;
int k;
T a[N];
const ll INF=(ll)1e10;
const ll H=(ll)3e9;

map<ll, int> aib;

void clr() {
  aib.clear();
}

void add(ll i,int x) {
  i+=H;
  assert(i>0);
  while (i<=INF) {
    aib[i]+=x;
    i+=i&(-i);
  }
}

int get(ll i) {
  i+=H;
  if(i<=0) return 0;
  assert(i>0);
  int sol=0;
  while(i) {
    sol+=aib[i];
    i-=i&(-i);
  }

  return sol;
}

ll how_many_under(ll d) {
  clr();
  ll sol=0;
  int pt=1;
  for (int i=1;i<=n;i++) {
    while (a[i].x-a[pt].x>d) add(a[pt++].y,-1);
    sol+=get(a[i].y+d)-get(a[i].y-d-1);
    add(a[i].y,+1);
  }
  return sol;
}

signed main() {
#ifdef ONLINE_JUDGE
  home = 0;
#endif

 /// home=0;

  if (home) {
    freopen("I_am_iron_man", "r", stdin);
  }
  else {
    ios::sync_with_stdio(0); cin.tie(0);
  }

  cin>>n>>k;

  for (int i=1;i<=n;i++) {
    int x,y;
    cin>>x>>y;
    a[i]={x+y, x-y};
  }

  sort(a+1,a+n+1,cmpTx);

  ll low=0,high=(ll)1e10,sol=-1;

  while (low<=high) {
    ll mid=(low+high)/2;
    if(how_many_under(mid)<=k) {
      sol=mid;
      low=mid+1;
    }else{
      high=mid-1;
    }
  }
  vector<ll> v;
  int pt=1;
  for (int i=1;i<=n;i++) {
    while (a[i].x-a[pt].x>sol) pt++;

    for (int j=pt;j<i;j++) {

      if(abs(a[i].y-a[j].y)<=sol){
        v.push_back(max(a[i].x-a[j].x,abs(a[i].y-a[j].y)));
      }
    }
  }
  sort(v.begin(),v.end());
  assert((int)v.size()<=k);
  v.resize(k, sol+1);
  for (auto &x: v) {
    cout<<x<<"\n";
  }
}

Compilation message (stderr)

road_construction.cpp: In function 'int main()':
road_construction.cpp:73:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |     freopen("I_am_iron_man", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 6
• Subtask 3: 0 / 7
• Subtask 4: 0 / 20
• Subtask 5: 0 / 27
• Subtask 6: 0 / 35