Submission #698827

#	Time	Username	Problem	Language	Result	Execution time	Memory
698827		NemanjaSo2005	Aliens (IOI16_aliens)	C++14	4 / 100	2 ms	468 KiB

aliens

#include "aliens.h"
#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll N,M,K;
ll dp[100005],c1=0,v1,c2=1e6,v2,cnt[100005];
struct tacka{
   ll x,y;/// X i Y su kao u matematici
} tniz[100005],niz[100005],tpp;
stack<tacka> S;
bool pox(tacka a,tacka b){
   if(a.x<b.x)
      return true;
   if(a.x>b.x)
      return false;
   return a.y<b.y;
}
ll koliko(ll x,ll y,ll px,ll py){
   ll r=abs(x-y);
   ll d=r+1;
   if((x-px)>=d)
      return d*d;
   ll a=d*d-(d-(x-px))*(d-(x-px));
   return a;
}
struct funk{
   ll offset,slope;
   int id;
   ll evaluiraj(ll gde){
      return gde*slope+offset;
   }
}pp;
vector<funk> C;
void dodaj(funk x){
   C.push_back(x);
}
int koja(ll gde){
   if(C.size()==0)
      return 0;
   int ret=0;
   ll vred=C[0].evaluiraj(gde);
   for(int i=1;i<C.size();i++){
      ll v2=C[i].evaluiraj(gde);
      if(v2<vred){
         vred=v2;
         ret=i;
      }
   }
   return ret;
}
ll izracunaj(ll lmb){
   dp[0]=0;
   cnt[0]=0;
   for(ll i=1;i<=N;i++){
      dp[i]=dp[i-1]+koliko(niz[i].x,niz[i].y,niz[i-1].x,niz[i-1].y)-lmb;
      cnt[i]=cnt[i-1]+1;
 
      int j=koja(niz[i].x);
      ll vred=koliko(niz[i].x,niz[j].y,niz[j-1].x,niz[j-1].y)+dp[j-1]-lmb;
      if(vred<dp[i]){
         dp[i]=vred;
         cnt[i]=cnt[j-1]+1;
      }
 
     /// pp;
      ///d=x-niz[i].y+1;
      if(-niz[i-1].x>=-niz[i].y+1){
         /// (x-niz[i].y+1)*(x-niz[i].y+1)
         /// x*x - 2*(niz[i].y+1) * x + (niz[i].y+1)*(niz[i].y+1)
         pp.slope=- 2*(niz[i].y+1);
         pp.offset=(niz[i].y+1)*(niz[i].y+1);
      }
      else{
         ///(d*d)-(d-(x-niz[i-1].x))*(d-(x-niz[i-1].x))
         ///(d-(x-niz[i-1].x))=(x-niz[i].y+1-(x-niz[i-1].x))=(x-niz[i].y+1-x+niz[i-1].x)=(-niz[i].y+1+niz[i-1].x)
         ///x*x - 2*(niz[i].y+1) * x + (niz[i].y+1)*(niz[i].y+1) -(-niz[i].y+1+niz[i-1].x)
         pp.slope= - 2*(niz[i].y+1);
         pp.offset=(niz[i].y+1)*(niz[i].y+1) -(-niz[i].y+1+niz[i-1].x)+dp[i];
      }
      dodaj(pp);
   }
   if(cnt[N]<=K and cnt[N]>c1){
      c1=cnt[N];
      v1=dp[N]+lmb*cnt[N];
   }
   if(cnt[N]>K and cnt[N]<c2){
      c2=cnt[N];
      v2=dp[N]+lmb*cnt[N];
   }
   return dp[N]+lmb*cnt[N];
}
long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
   /*while(true){
      ll a,b,c,d;
      cin>>a>>b>>c>>d;
      cout<<koliko(a,b,c,d)<<endl;
   }*/
   N=n;
   M=m;
   K=k;
   for(ll i=1;i<=N;i++){
      tniz[i].x=c[i-1]+1;
      tniz[i].y=r[i-1]+1;
   }
   for(ll i=1;i<=N;i++)
      if(tniz[i].x<tniz[i].y)
         swap(tniz[i].x,tniz[i].y);
   sort(tniz+1,tniz+1+N,pox);
   tpp.x=-1;
   tpp.y=-1e9;
   S.push(tpp);
  // cout<<N<<endl;
   //for(ll i=1;i<=N;i++)
    //  cout<<tniz[i].x<<" "<<tniz[i].y<<endl;
   for(ll i=1;i<=N;i++){
      if(S.top().x==tniz[i].x)
         continue;
      while(S.top().y>=tniz[i].y)
         S.pop();
      S.push(tniz[i]);
   }
   for(ll i=1;i<=N;i++){
      niz[i].x=0;
      niz[i].y=0;
   }
   N=S.size()-1;
   for(ll i=N;i>=1;i--){
      niz[i]=S.top();
      S.pop();
   }
   //cout<<N<<endl;
   //for(ll i=1;i<=N;i++)
    //  cout<<niz[i].x<<" "<<niz[i].y<<endl;
   if(K>N)
      K=N;
   niz[0].x=niz[0].y=-1e9;
   ll dg=-M*M,ret=0,gg=0,sred;
   while(dg<=gg){
      sred=(dg+gg)/2;
      izracunaj(sred);
      if(cnt[N]<=K){
         dg=sred+1;
         ret=dg;
      }
      else
         gg=sred-1;
   }
   ll res=v1;
   res=min(res,v1+((v2-v1)/(c2-c1))*(K-c1));
   dg=-M*M;
   gg=ret;
   ll v1,v2;
   while(dg<=gg){
      sred=(dg+gg)/2;
      v1=izracunaj(sred-1);
      v2=izracunaj(sred);
      res=min(res,v1);
      res=min(res,v2);
      if(v2<v1)
         dg=sred+1;
      else
         gg=sred-1;
   }
   return res;
}

Compilation message (stderr)

aliens.cpp: In function 'int koja(long long int)':
aliens.cpp:42:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<funk>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |    for(int i=1;i<C.size();i++){
      |                ~^~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 0 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40