Submission #1047374

#	Time	Username	Problem	Language	Result	Execution time	Memory
1047374		Minbaev	Watching (JOI13_watching)	C++17	100 / 100	642 ms	7768 KiB

watching

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> 
 
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")
 
using namespace std;
using namespace __gnu_pbds;
 
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define f first
#define s second
#define int long long
#define ll long long
#define pii pair<int,int>
#define ar array
 
template<class T>bool umax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool umin(T &a,T b){if(b<a){a=b;return true;}return false;}
 
typedef tree<int, null_type, less_equal<int>, rb_tree_tag,
 tree_order_statistics_node_update> ordered_set;
 
const int inf = 1e17 + 7;
const int mod = 1e9 + 7;
const int N = 3e5 + 5;
const int md = 998244353;
 
int binpow(int a, int b){
	if(b == 0)return 1;
	if(b % 2 == 0){
		int c = binpow(a,b/2);
		return (c*c)%mod;
	}
	return (binpow(a,b-1)*a)%mod;
}
 
int divi(int a, int b){
	return (a*(binpow(b,mod-2)))%mod;
}
 
int n,m,k;
 
void solve(){
	
	cin >> n >> m >> k;
	
	vector<int>v(n+1);
	for(int i = 1;i<=n;i++)cin >> v[i];
	
	sort(all(v));
	
	if(m+k >= n){
		cout << 1 << "\n";
		return;
	}
	
	//~ for(auto to:v)cout << to << " ";
	//~ cout << "\n";
	
	int l = 2, r = 1e9, ans = -1;
	while(l <= r){
		int mid = (l+r)/2;
		
		bool flag = false;
		int dp[m+1][k+1]{};
		for(int i = 0;i<=m;i++){
			for(int j = 0;j<=k;j++){
				if(i >= 1){
					int h = v[dp[i-1][j] + 1] + mid - 1;
					int u = upper_bound(all(v), h) - v.begin() - 1;
					umax(dp[i][j], u);
				}
				if(j >= 1){
					int h = v[dp[i][j-1] + 1] + 2*mid - 1;
					int u = upper_bound(all(v), h) - v.begin() - 1;
					umax(dp[i][j], u);
				}
				if(dp[i][j] == n)flag = true;
			}
		}
		
		if(flag){
			r = mid - 1;
			ans = mid;
		}
		else l = mid + 1;
		
		
	}
	
	cout << ans << "\n";
	
}
/*
 
*/
 signed main()
{
//	freopen("seq.in", "r", stdin);
//  freopen("seq.out", "w", stdout);
	//~ ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
	int tt=1;//cin>>tt;
	while(tt--)solve();
 
}
 

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