Submission #51459

#	Time	Username	Problem	Language	Result	Execution time	Memory
51459		vivukhue	Watching (JOI13_watching)	C++14	100 / 100	126 ms	16380 KiB

watching

#include <bits/stdc++.h>
#define fw(i,l,r) for (int i=l;i<r;i++)

using namespace std;
int n,p,q;
int a[2001];
int fars[2001];
int farl[2001];
int dp[2001][2001];

bool check(int w)
{
    for(int i=0;i<n;i++)
    {
        fars[i] = upper_bound(a,a+n,a[i]+w-1) - a;
        farl[i] = upper_bound(a,a+n,a[i]+2*w-1) - a;
    }
    memset(dp,-1,sizeof(dp));
    dp[0][0] = 0;
    for(int i=0;i<=p;i++)
    {
        for(int j=0;j<=q;j++)
        {
            if(dp[i][j]!=-1)
            {
                if(dp[i][j]==n)
                    return true;
                dp[i+1][j] = max(dp[i+1][j],fars[dp[i][j]]);
                dp[i][j+1] = max(dp[i][j+1],farl[dp[i][j]]);
            }
        }
    }

    return false;
}

signed main()
{
    cin>>n>>p>>q;
    for(int i=0;i<n;i++)
        cin>>a[i];

    if(p+q>=n)
    {
        cout<<1;
        return 0;
    }

    sort(a,a+n);
    //for(int i=0;i<n;i++)
        //cout<<a[i]<<" ";

    int L=1,R=1e9;
    while(L!=R)
    {
        int mid = (L+R)/2;
        if(check(mid))
            R = mid;
        else
            L = mid+1;
    }

    cout<<L;
}

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