Submission #444361

#	Time	Username	Problem	Language	Result	Execution time	Memory
444361		fuad27	Watching (JOI13_watching)	C++14	100 / 100	579 ms	32152 KiB

watching

#include<bits/stdc++.h>
using namespace std;
#define int long long
int n, p, q;
vector<int> A;
vector<vector<int>> dp(2010, vector<int> (2010, 0));
bool can(int w) {
	int a = 0, b = 0;
	dp[0][0] = 0;
	int I = min(n, p);
	int J = min(n, q);
	for(int i = 0;i<=I;i++) {
		for(int j = 0;j<=J;j++) {
			if(i == 0 and j == 0) continue;
            		if(i > 0)
            		{
                		a=dp[i-1][j];
				b = a;
                		while(a<n and A[b]+w-1>=A[a])
					a++;
            		}
            		dp[i][j]=a;
        	    	if(j > 0)
	        	{
	            		a=dp[i][j-1];
				b = a;
        			while(a<n and A[b]+2*w-1>=A[a])
					a++;
            		}
            		dp[i][j]=max(a, dp[i][j]);
		}
	}
	return (dp[I][J]>=n);
}
int32_t main () {
	cin >> n >> p >> q;
	for(int i = 0;i<n;i++) {
		int ai;
		cin >> ai;
		A.push_back(ai);
	}
	sort(A.begin(), A.end());
	int r = 1e9, l = 1, ans = 0;
	while(l<=r) {
		int mid = (l+r)/2;
		if(can(mid)) {
			ans = mid;
			r = mid - 1;
		}
		else {
			l = mid + 1;
		}
	}
	cout<<l<<endl;
	return 0;
}

Compilation message (stderr)

watching.cpp: In function 'int32_t main()':
watching.cpp:43:22: warning: variable 'ans' set but not used [-Wunused-but-set-variable]
   43 |  int r = 1e9, l = 1, ans = 0;
      |                      ^~~

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