Submission #748219

#	Time	Username	Problem	Language	Result	Execution time	Memory
748219		mariowong	Watching (JOI13_watching)	C++14	100 / 100	283 ms	16052 KiB

watching

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

int a[2005],dp[2005][2005],large_range[2005],small_range[2005];
int main(){
	ios::sync_with_stdio(false);
	int n,p,q;
	cin >> n >> p >> q;
	for (int i=1;i<=n;i++) cin >> a[i];
	sort(a+1,a+1+n);
	int L=1,R=1000000000;
	while (L < R){
		int mid=(L+R)/2;
		int ptrL=0,ptrS=0;
		for (int i=1;i<=n;i++){
			while (a[i]-a[ptrL+1] >= mid*2) ptrL++;
			while (a[i]-a[ptrS+1] >= mid) ptrS++;
			large_range[i]=ptrL; small_range[i]=ptrS;
		}
		for (int i=0;i<=n;i++){
			for (int j=0;j<=min(n,q);j++){
				dp[i][j]=1e9;
			}
		}
		for (int i=0;i<=min(n,q);i++) dp[0][i]=0; 
		for (int i=1;i<=n;i++){
			for (int j=0;j<=min(n,q);j++){
				dp[i][j]=dp[small_range[i]][j]+1;
				if (j != 0) dp[i][j]=min(dp[i][j],dp[large_range[i]][j-1]);
			}
		}
		if (dp[n][min(n,q)] <= p) R=mid;
		else L=mid+1;
	}
	cout << L << "\n";
	return 0;
}

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