Submission #132810

#	Time	Username	Problem	Language	Result	Execution time	Memory
132810		miguel	Watching (JOI13_watching)	C++14	100 / 100	425 ms	31864 KiB

watching

#include<bits/stdc++.h>
//#include<gondola.h>
using namespace std;
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define dbg(x) cout << #x << '=' << x << '\n';
#define ll long long
#define int ll
#define sz size()
#define x first
#define y second
#define pi pair <int, int>
#define pii pair <int, pi>
#define vi vector <int>
const ll mod = 998244353;
int n, p, q, dp[2005][2005];
int w[2005];

bool check(int d){
    for(int i=0; i<=n; i++){
        for(int j=0; j<=p; j++) dp[i][j]=1e18;
    }
    dp[0][0]=0;
    for(int j=1; j<=p; j++) dp[0][j]=0;
    for(int i=0; i<n; i++){
        int x=(upper_bound(w+1, w+n+1, w[i+1]+d-1)-w)-1;
        int y=(upper_bound(w+1, w+n+1, w[i+1]+2*d-1)-w)-1;
        for(int j=0; j<=p; j++){
            if(j<p) dp[x][j+1]=min(dp[x][j+1], dp[i][j]);
            dp[y][j]=min(dp[y][j], dp[i][j]+1);
        }
    }
    /*if(d<=8)cout<<d<<"\n";
    if(d<=8){
        for(int i=0; i<=n; i++){
            for(int j=0; j<=p; j++){
                cout<<dp[i][j]<<" ";
            }cout<<endl;
        }
        cout<<endl;
    }*/
    return (dp[n][p]<=q);
}

int32_t main(){
    ios_base :: sync_with_stdio(0); cin.tie(); cout.tie();
    cin>>n>>p>>q;
    p=min(p, n);
    for(int i=1; i<=n; i++){
        cin>>w[i];
    }
    int l=0, r=1e9+1;
    sort(w+1, w+n+1);
    //w.pb(1000000001);
    while(r-l>1){
        int mid=(l+r)>>1;
        if(check(mid)) r=mid;
        else l=mid;
    }
    cout<<r;
}

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