Submission #911173

#	Time	Username	Problem	Language	Result	Execution time	Memory
911173		Acanikolic	Watching (JOI13_watching)	C++14	0 / 100	1094 ms	80452 KiB

watching

#include <bits/stdc++.h>
		 		
#define int long long 
		 
#define pb push_back 
		
#define F first
		 
#define S second
		 
using namespace std;
		 
const int N = 2000 + 10;
		 
const int mod = 1e9 + 7;
		 
const int inf = 1e18;	

int n,p,q,a[N];
				
bool check(int x) {
	vector<vector<int>>dp(n + 1,vector<int>(p + 2,inf));
	for(int i = 0; i <= p; i++) dp[0][i] = 0;
	for(int i = 1; i <= n; i++) {
		for(int j = 0; j <= p; j++) {
			if(j > 0) dp[i][j] = min(dp[i][j],dp[i - 1][j - 1]);
			dp[i][j] = min(dp[i][j],dp[i - 1][j] + 1);
			int l = i,r = n,ans = -1;
			while(l <= r) {
				int mid = (l + r) / 2;
				if(a[i] + x - 1 >= a[mid]) {
					ans = mid;
					l = mid + 1;
				}else {
					r = mid - 1;
				}
			}
			if(ans != -1) dp[ans][j + 1] = min(dp[ans][j + 1],dp[i - 1][j]);
			l = i,r = n,ans = -1;
			while(l <= r) {
				int mid = (l + r) / 2;
				if(a[i] + 2 * x - 1 >= a[mid]) {
					ans = mid;
					l = mid + 1;
				}else {
					r = mid - 1;
				}
			}
			if(ans != -1) dp[ans][j] = min(dp[ans][j],dp[i - 1][j] + 1);
		}
	}
	if(dp[n][p] <= q) return true;
	return false;
	for(int i = 1; i <= n; i++) {
		for(int j = 0; j <= p; j++) cout << dp[i][j] << " ";
		cout << endl;
	}
}				
																						
signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
	
	cin >> n >> p >> q;
	for(int i = 1; i <= n; i++) cin >> a[i];
	sort(a + 1,a + n + 1);
	int l = 1,r = 1e9,ans = -1;
	while(l <= r) {
		int mid = (l + r) / 2;
		if(check(mid)) {
			ans = mid;
			r = mid - 1;
		}else {
			l = mid + 1;
		}
	}
	cout << ans;
	//cout << check(9);
    return 0; 
}

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