oj.uz

Submission #365304

# Submission time Handle Problem Language Result Execution time Memory
365304 2021-02-11T12:11:34 Z Bill_00 Watching (JOI13_watching) C++14
50 / 100
 151 ms 16108 KB 
#include <bits/stdc++.h>
using namespace std;
int a[2001];
int dp[2001][2001];
int pre1[2001],pre2[2001];
int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n,p,q;
	cin >> n >> p >> q;
	for(int i=1;i<=n;i++){
		cin >> a[i];
	}
	sort(a+1,a+n+1);
	if(p+q>=n){
		cout << 1;
		return 0;
	}
	int l=1,r=1000000000;
	while(l!=r){
		int mid=l+r>>1;
		int k=0,y=0;
		for(int i=1;i<=p;i++){
			dp[0][i]=0;
		}
		for(int i=1;i<=n;i++){
			dp[i][0]=1e9;
			while((a[i]-mid)>=a[k+1]) k++;
			while((a[i]-2*mid)>=a[y+1]) y++;
			pre1[i]=k;
			pre2[i]=y;
		}
		for(int i=1;i<=n;i++){
			for(int j=1;j<=p;j++){
				int id=pre1[i];
				int id1=pre2[i];
				dp[i][j]=min(dp[id][j-1],dp[id1][j]+1);
			}
		}
		if(dp[n][p]>q){
			l=mid+1;
		}
		else r=mid;
	}
	//cout << l << endl;
	int mid=l,k=0,y=0;
	for(int i=1;i<=p;i++){
		dp[0][i]=0;
	}
	for(int i=1;i<=n;i++){
		dp[i][0]=1e9;
		while((a[i]-mid)>=a[k+1]) k++;
		while((a[i]-2*mid)>=a[y+1]) y++;
		pre1[i]=k;
		pre2[i]=y;
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=p;j++){
			int id=pre1[i];
			int id1=pre2[i];
			dp[i][j]=min(dp[id][j-1],dp[id1][j]+1);
			//cout << dp[i][j] << ' ' << i << ' ' << j << endl;
		}
	}
	if(dp[n][p]>q){
		l++;
	}
	mid=l-1,k=0,y=0;
	for(int i=1;i<=p;i++){
		dp[0][i]=0;
	}
	for(int i=1;i<=n;i++){
		dp[i][0]=1e9;
		while((a[i]-mid)>=a[k+1]) k++;
		while((a[i]-2*mid)>=a[y+1]) y++;
		pre1[i]=k;
		pre2[i]=y;
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=p;j++){
			int id=pre1[i];
			int id1=pre2[i];
			dp[i][j]=min(dp[id][j-1],dp[id1][j]+1);
			//cout << dp[i][j] << ' ' << i << ' ' << j << endl;
		}
	}
	if(dp[n][p]<=q){
		l--;
	}
	cout << l;
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:22:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   22 |   int mid=l+r>>1;
      |           ~^~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 748 KB Output is correct
2 Correct 0 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 0 ms 364 KB Output is correct
5 Correct 0 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 748 KB Output is correct
8 Correct 1 ms 748 KB Output is correct
9 Correct 1 ms 748 KB Output is correct
10 Correct 1 ms 748 KB Output is correct
11 Correct 1 ms 748 KB Output is correct
12 Correct 1 ms 748 KB Output is correct
13 Correct 1 ms 748 KB Output is correct
14 Correct 1 ms 748 KB Output is correct
15 Correct 1 ms 748 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 8556 KB Output is correct
2 Correct 0 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 9 ms 8576 KB Output is correct
8 Correct 18 ms 9296 KB Output is correct
9 Correct 73 ms 14316 KB Output is correct
10 Correct 151 ms 16108 KB Output is correct
11 Correct 15 ms 9068 KB Output is correct
12 Correct 94 ms 16108 KB Output is correct
13 Correct 8 ms 8556 KB Output is correct
14 Correct 9 ms 8556 KB Output is correct
15 Incorrect 9 ms 8556 KB Output isn't correct