Submission #923732

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
923732	2024-02-07T16:44:12 Z	Lalic	Watching (JOI13_watching)	C++17	100 / 100	529 ms	32156 KB

watching

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define all(x) x.begin(), x.end()
#define allr(x) x.rbegin(), x.rend()
#define int long long

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 1e5+10;
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3f;
const int MOD = 1e9+7;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, p, q;
vector<int> arr;

bool check(int w){
	vector<vector<int>> dp(n+1, vector<int>(p+1, INF));
	dp[0][0]=0;
	
	int ptr1=0, ptr2=0;
	for(int i=1;i<=n;i++){
		while(arr[ptr1+1]<=arr[i]-w) ptr1++;
		while(arr[ptr2+1]<=arr[i]-2*w) ptr2++;
		
		for(int j=0;j<=p;j++){
			if(j) dp[i][j]=min(dp[i][j], dp[ptr1][j-1]);
			dp[i][j]=min(dp[i][j], dp[ptr2][j]+1);
		}
	}
	
	int mn=INF;
	for(int i=0;i<=p;i++) mn=min(mn, dp[n][i]);
	
	return mn<=q;
}

void solve(){
	cin >> n >> p >> q; p=min(p, n);
	arr.resize(n+1); arr[0]=-INF;
	for(int i=1;i<=n;i++) cin >> arr[i];
	sort(arr.begin()+1, arr.end());
	
	int l=1, r=5e8, best=-1;
	while(l<=r){
		int mid=(l+r)>>1;
		if(check(mid)){
			best=mid;
			r=mid-1;
		}
		else l=mid+1;
	}
	
	cout << best << "\n";
}

int32_t main(){
	ios_base::sync_with_stdio(false); cin.tie(NULL);
		
	int tt=1;
	//cin >> tt;
	while(tt--) solve();
	return 0;
}

Subtask #1

50.0 / 50.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	344 KB	Output is correct
2	Correct	1 ms	348 KB	Output is correct
3	Correct	0 ms	456 KB	Output is correct
4	Correct	1 ms	348 KB	Output is correct
5	Correct	1 ms	464 KB	Output is correct
6	Correct	1 ms	348 KB	Output is correct
7	Correct	1 ms	344 KB	Output is correct
8	Correct	0 ms	456 KB	Output is correct
9	Correct	1 ms	344 KB	Output is correct
10	Correct	1 ms	348 KB	Output is correct
11	Correct	1 ms	348 KB	Output is correct
12	Correct	1 ms	348 KB	Output is correct
13	Correct	1 ms	348 KB	Output is correct
14	Correct	0 ms	348 KB	Output is correct
15	Correct	1 ms	348 KB	Output is correct

Subtask #2

50.0 / 50.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	604 KB	Output is correct
2	Correct	0 ms	348 KB	Output is correct
3	Correct	373 ms	24176 KB	Output is correct
4	Correct	529 ms	32000 KB	Output is correct
5	Correct	17 ms	1884 KB	Output is correct
6	Correct	523 ms	32156 KB	Output is correct
7	Correct	4 ms	600 KB	Output is correct
8	Correct	28 ms	2568 KB	Output is correct
9	Correct	185 ms	12500 KB	Output is correct
10	Correct	493 ms	30380 KB	Output is correct
11	Correct	20 ms	1996 KB	Output is correct
12	Correct	242 ms	16012 KB	Output is correct
13	Correct	4 ms	612 KB	Output is correct
14	Correct	5 ms	844 KB	Output is correct
15	Correct	5 ms	900 KB	Output is correct