Submission #1284637

#	Time	Username	Problem	Language	Result	Execution time	Memory
1284637		Faisal_Saqib	Watching (JOI13_watching)	C++20	50 / 100	1095 ms	16340 KiB

watching

/* 
    VENI VIDI VICI
*/

// #pragma GCC optimize("Ofast","unroll-all-loops","fast-math","no-stack-protector","give-no-fuck")
#include <bits/stdc++.h>
// #include <iostream>
// #include <vector>
// #include <algorithm>
// #include <set>
// #include <map>

using namespace std;
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()

#define rep(i,x, n) for (int i = (x); i < (n); ++i)
#define repr(i,x, n) for (int i = (n) - 1; i >= (x); --i)
mt19937 RNG(chrono::steady_clock::now().time_since_epoch().count());  
// #define sum accumulate

//using i128 = __int128;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using str = string;
using pi = pair<int, int>;
using pl = pair<ll, ll>;

using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pair<int, int>>;
using vvi = vector<vi>;
using sll = set<ll>;

template<class T>
istream& operator>>(istream& is, vector<T>& v) {
    for(auto &i:v) is>>i;
    return is;
}
template<class T1,class T2>
istream& operator>>(istream& is, pair<T1,T2>& p) {
    is>>p.fi>>p.se;
    return is;
}
template<class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    for(const auto &i:v) os<<i<<' ';
    return os;
}
template<class T1,class T2>
ostream& operator<<(ostream& os, const pair<T1,T2>& p) {
    os<<p.fi<<' '<<p.se; return os;
}
void pyn(bool x)
{
    cout<<(x?"YES":"NO")<<endl;
}
void pYN(bool x)
{
    cout<<(x?"Yes":"No")<<endl;
}
void pAB(bool x)
{
    cout<<(x?"Alice":"Bob")<<endl;
}
ll powmod(ll a,ll b,ll modulo)
{
  if(b==0){
    return 1;
  }
  ll temp=powmod(a,b/2,modulo);
  if(b%2==0){
    return (temp*temp)%modulo;
  }
  else{
    return (a*((temp*temp)%modulo))%modulo;
  }
}
bool Prime(ll n){
    for (ll i = 2; i*i <= n; i++)
        if (n % i == 0)
            return false;
    return (n>1);
}
void readIO() {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
}

void solve();

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    // readIO();

    int uwu=1;

    // cin>>uwu;

    for(int tc=1;tc<=uwu;tc++) {
        // cout<<"Case #"<<tc<<": ";
        solve();
    }
    return 0;
}
const int N=2e3+10;
int dp[N][N];
void solve()
{
    ll n,p,q;
    cin>>n>>p>>q;
    p=min(p,n);
    q=min(q,n);
    vl a(n);
    cin>>a;
    sort(all(a));
    ll s=0,e=1e9+1;
    while(s+1<e)
    {
        ll w=(s+e)/2;
        ll w2=w+w;
        for(int i=0;i<=n;i++)
        {
            for(int j=0;j<=n;j++)
            {
                dp[i][j]=n+2;
            }
        }
        dp[0][0]=0;
        for(int i=1;i<=n;i++)
        {
            for(int j=0;j<=q;j++) // use large cameras
            {
                // use large
                if(j>0)
                {
                    auto it=lower_bound(all(a),a[i-1]-w2+1);// smallest value in want [a[i-1]-w+1,a[i-1]]
                    int ip=it-begin(a);
                    dp[i][j]=min(dp[i][j],dp[ip][j-1]);
                }
                //use small
                auto it=lower_bound(all(a),a[i-1]-w+1);// smallest value in want [a[i-1]-w+1,a[i-1]]
                int ip=it-begin(a);
                dp[i][j]=min(dp[i][j],dp[ip][j]+1);
            }
        }
        bool pos=0;
        for(int j=0;j<=q;j++)
        {
            if(dp[n][j]<=p)
            {
                pos=1;
            }
        }
        if(pos)
        {
            e=w;
        }
        else{
            s=w;
        }
    }
    cout<<e<<endl;
}

Compilation message (stderr)

watching.cpp: In function 'void readIO()':
watching.cpp:90:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:91:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 50 / 50
• Subtask 2: 0 / 50