Submission #521376

#	Time	Username	Problem	Language	Result	Execution time	Memory
521376		amunduzbaev	Watching (JOI13_watching)	C++14	100 / 100	366 ms	16196 KiB

watching

#include "bits/stdc++.h"
using namespace std;
 
#define ar array

const int N = 2e3 + 5;
int a[N], n, p, q;
int dp[N][N], pw[N], p2w[N];

signed main(){
	ios::sync_with_stdio(0); cin.tie(0);
	
	cin>>n>>p>>q;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	} sort(a + 1, a + n + 1);
	p = min(p, n), q = min(q, n);
	
	auto check = [&](int w){
		memset(dp, 127, sizeof dp);
		memset(pw, -1, sizeof pw);
		memset(p2w, -1, sizeof p2w);
		for(int i=1;i<=n;i++){
			for(int j=i-1;j>0;j--){
				if(a[i] - a[j] + 1 > w && pw[i] == -1) pw[i] = j;
				if(a[i] - a[j] + 1 > 2 * w && p2w[i] == -1) p2w[i] = j;
			} if(pw[i] == -1) pw[i] = 0;
			if(p2w[i] == -1) p2w[i] = 0;
		}
		
		for(int i=0;i<N;i++) dp[0][i] = 0;
		for(int i=1;i<=n;i++){
			for(int j=0;j<=n;j++){
				if(j > 0) dp[i][j] = min(dp[i][j], dp[pw[i]][j - 1]);
				dp[i][j] = min(dp[i][j], dp[p2w[i]][j] + 1);
			}
		}
		
		return (dp[n][p] <= q);
	};
	
	int l = 1, r = 1e9;
	while(l < r){
		int m = (l + r) >> 1;
		if(check(m)) r = m;
		else l = m + 1;
	}
	
	//~ cout<<check(l)<<" ";
	cout<<l<<"\n";
}

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