Submission #917320

#	Time	Username	Problem	Language	Result	Execution time	Memory
917320		NintsiChkhaidze	Watching (JOI13_watching)	C++17	100 / 100	231 ms	16212 KiB

watching

#include <bits/stdc++.h>
#define ll long long
#define s second
#define f first
#define pb push_back
using namespace std;

const int N = 2e3 + 3,inf = 1e9;
int a[N],dp[N][N],n,p,q,arr[N];

int find(int i){
	int l = 1,r = n,res = 0;
	while (l <= r){
		int mid = (l + r)/2;
		if (a[mid] < i){
			res = mid;
			l = mid + 1;
		}else{
			r = mid - 1;
		}
	}
	return res;
}

bool check(int w){
	for (int i = 0; i <= n; i++)
		for (int j = 0; j <= p; j++)
			dp[i][j] = inf;
			
	dp[0][0] = 0;
	for (int i = 1; i <= n; i++){
		int l1 = find(a[i] - w + 1);
		int l2 = find(a[i] - 2*w + 1);
		for (int j = 0; j <= p; j++){
			//davsvat patara
			dp[i][j + 1] = min(dp[i][j + 1],dp[l1][j]);

			//davsvat didi
			dp[i][j] = min(dp[i][j],dp[l2][j] + 1);
		}
	}

	for (int i = 0; i <= p; i++)
		if (dp[n][i] <= q) return 1;
	return 0;
}
signed main() {
	ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
	 
	cin >> n >> p >> q;
	for (int i = 1; i <= n; i++)
		cin >> arr[i];
	sort(arr+1,arr+n+1);

	int m = 0;
	for (int i = 1; i <= n; i++){
		if (i == n || arr[i] != arr[i + 1]) {
			a[++m] = arr[i];
		}
	}
	n = m;

	p = min(p,n);
	q = min(q,n);

	int l = 0,r = 1e9,res=-1;
	while (l <= r){
		int w = (l + r) >> 1;
		if (check(w)) {
			res = w;
			r = w - 1;
		}else{
			l = w + 1;
		}
	}
	cout<<res;
}

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