Submission #210834

#	Time	Username	Problem	Language	Result	Execution time	Memory
210834		Nucleist	Watching (JOI13_watching)	C++14	100 / 100	932 ms	71524 KiB

watching

#include <bits/stdc++.h> 
using namespace std; 
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#define flash ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define debug(x) cerr << " - " << #x << ": " << x << endl;
#define debugs(x, y) cerr << " - " << #x << ": " << x << " " << #y << ": " << y << endl;
#define all(x) (x).begin(),(x).end()
#define sz(x) (ll)x.size()
#define ll long long
#define INF 1000000000
#define MOD 1000000007
#define pb push_back
#define ve vector<ll>
#define dos pair<ll,ll>
#define vedos vector<dos>
#define rand mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
struct greateri
{
    template<class T>
    bool operator()(T const &a, T const &b) const { return a > b; }
};
ll n,p,q,w;
set<ll> hed;
ve hedi;
map<ll,ll>pos;
ll dp[3001][3001];
ll next1[3001][2];
ll solve(ll index,ll rem)
{
    if(index==(hed.size()-1))return 0;
    if(dp[index][rem]!=-1)return dp[index][rem];
    ll ans=pow(10,16);
    if(rem>0)
    {
        ans=min(ans,solve(next1[index][1],rem-1));
    }
    {
        ans=min(ans,1+solve(next1[index][0],rem));
    }
    return dp[index][rem]=ans;
}
int main()
{
  //flash;
  cin>>n>>p>>q;
  memset(dp,-1,sizeof dp);
  for (ll i = 0; i < n; ++i)
  {
    ll xo;
    cin>>xo;
    hed.insert(xo);
  }
  hed.insert(30000000000);
  ll ans=-1;
  for(auto it:hed){hedi.pb(it);pos[it]=hedi.size()-1;}
  ll low=1;
  ll high=INF;
  while(low<=high)
  {
    ll med=(low+high)/2;
    w=med;
    for (int i = 0; i < n; ++i)
    {
       auto u=hed.lower_bound(hedi[i]+w);
       auto k=pos[(*u)];
       next1[i][0]=k;
       u=hed.lower_bound(hedi[i]+2*w);
       k=pos[(*u)];
       next1[i][1]=k;
    }
    memset(dp,-1,sizeof dp);
    ll k = solve(0,min(q,n));
    if(k<=p)
    {
        ans=med;
        high=med-1;
    }
    else
    {
        low=med+1;
    }
  }
  cout<<ans;
  return 0;
}
//code the AC sol !
// BS/queue/map

Compilation message (stderr)

watching.cpp:4:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("O3")
 
watching.cpp:5:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("unroll-loops")
 
watching.cpp: In function 'long long int solve(long long int, long long int)':
watching.cpp:32:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(index==(hed.size()-1))return 0;
        ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50