Submission #1278163

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278163		tung04885	구경하기 (JOI13_watching)	C++20	100 / 100	181 ms	16412 KiB

watching

#include <bits/stdc++.h>
using namespace std;
#define MAX 2020

int n,P,Q;
int a[MAX]={};

void nhap()
{
    cin>>n>>P>>Q;
    for(int i=1;i<=n;i++) cin>>a[i];
}

int d[MAX][MAX];

bool check(int x)
{
    memset(d,0x3f,sizeof(d));
    for(int i=0;i<=P;i++) d[0][i]=0;
    int ptr1=1;
    int ptr2=1;
    for(int i=1;i<=n;i++)
    {
        while(a[i]-a[ptr1]+1>x) ptr1++;
        while(a[i]-a[ptr2]+1>2*x) ptr2++;
        for(int j=0;j<=P;j++)
        {
            if(j!=0) d[i][j]=min(d[i][j],d[ptr1-1][j-1]);
            d[i][j]=min(d[i][j],d[ptr2-1][j]+1);
        }
    }
    for(int i=0;i<=P;i++) if(d[n][i]<=Q) return 1;
    return 0;
}

void solve()
{
    nhap();
    if(P+Q>=n)
    {
        cout<<1;
        return;
    }
    sort(a+1,a+n+1);
    int l=1,r=1e9;
    int ans=1e9;
    while(l<=r)
    {
        int mid=l+r>>1;
        if(check(mid))
        {
            ans=mid;
            r=mid-1;
        }
        else l=mid+1;
    }
    cout<<ans;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(nullptr);
    solve();
    return 0;
}

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