Submission #1252695

#	Time	Username	Problem	Language	Result	Execution time	Memory
1252695		ilhan_arda	Watching (JOI13_watching)	C++20	50 / 100	4 ms	1864 KiB

watching

//~ #pragma GCC optimize("O3,unroll-loops")
//~ #pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define fi first
#define se second
#define pb push_back
#define endl "\n"
#define int long long
using namespace std;

typedef long long ll;
typedef pair<int, int> ii;
typedef tuple<int, int, int> iii;
const int inf  = INT_MAX;
const int mod  = 1e9+7;

int n, P, Q, w;
int a[105], dp[105][2005];
int f(int ind, int p){
	if(ind > n) return 0;
	if(dp[ind][p] != -1) return dp[ind][p];
	//kucuk
	int t1 = inf, t2 = inf;
	if(p){
		int ind2 = upper_bound(a+1, a+n+1, a[ind]+w-1) - a;
		//~ cout<<ind<<" .. "<<ind2<<" .. " << w<<endl;
		//~ if(a[ind] + w - 1 >= a[n])return true;
		t1 = f(ind2, p-1);
	}
	int ind2 = upper_bound(a+1, a+n+1, a[ind]+w*2-1) - a;
	//~ if(a[ind] + w*2 - 1 >= a[n])return true;
	t2 = f(ind2, p)+1;
	return dp[ind][p] = min(t1, t2);
}
bool check(int x){
	w = x;
	memset(dp, -1, sizeof(dp));
	if(f(1, P)<=Q){
		return true;
	}
	else return false;
}
int32_t main(){
	fast;
	cin>>n>>P>>Q;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	sort(a+1, a+n+1);

	if(P + Q >= n){
		cout<<1<<endl;
		return 0;
	}
	int l = 1, r = 1e9;
	while(l<=r){
		int m = (l+r)/2;
		if(check(m)){
			 r = m-1;
		}
		else l = m+1;
	}
	cout<<l<<endl;
}






//https://usaco.org/current/current/index.php?page=viewproblem2&cpid=282 bunu coz




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