Submission #1131363

#	Time	Username	Problem	Language	Result	Execution time	Memory
1131363		vladilius	Watching (JOI13_watching)	C++20	100 / 100	238 ms	16192 KiB

watching

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
const int inf = 1e9;

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, p, q; cin>>n>>p>>q;
    vector<int> a(n + 1);
    for (int i = 1; i <= n; i++){
        cin>>a[i];
    }
    sort(a.begin() + 1, a.end());
    vector<int> :: iterator it;
    
    p = min(p, n); 
    vector<vector<int>> dp(n + 1, vector<int>(p + 1));
    for (int j = 0; j <= p; j++) dp[0][j] = 0;
    
    auto check = [&](int w){
        for (int i = 1; i <= n; i++){
            for (int j = 0; j <= p; j++){
                dp[i][j] = inf;
            }
        }
        for (int i = 1; i <= n; i++){
            it = lower_bound(a.begin() + 1, a.end(), a[i] - w + 1);
            int t1 = (int) (it - a.begin()) - 1;
            it = lower_bound(a.begin() + 1, a.end(), a[i] - 2 * w + 1);
            int t2 = (int) (it - a.begin()) - 1;
            for (int j = 0; j <= p; j++){
                if (j < p) dp[i][j + 1] = min(dp[i][j + 1], dp[t1][j]);
                dp[i][j] = min(dp[i][j], dp[t2][j] + 1);
            }
        }
        return dp[n][p] <= q;
    };
    
    int l = 1, r = inf;
    while (l + 1 < r){
        int m = (l + r) / 2;
        if (check(m)){
            r = m;
        }
        else {
            l = m + 1;
        }
    }
    if (check(l)) r = l;
    
    cout<<r<<"\n";
}

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