oj.uz

Submission #707814

# Submission time Handle Problem Language Result Execution time Memory
707814 2023-03-10T08:38:09 Z Alihan_8 Watching (JOI13_watching) C++17
50 / 100
 1000 ms 31388 KB 
#include <bits/stdc++.h>
// include <ext/pb_ds/assoc_container.hpp>
// include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;
using namespace std;
#define all(x) x.begin(), x.end()
#define pb push_back
// define ordered_set tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>
#define mpr make_pair
#define ln '\n'
void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
#define int long long
const int N = 2e3+1;
int dp[N][N];
bool chmin(int &x, int y){
    bool flag = false;
    if ( x > y ){
        x = y; flag |= true;
    }
    return flag;
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n, P, Q; cin >> n >> P >> Q;
    chmin(P, n), chmin(Q, n);
    vector <int> p(n);
    for ( auto &i: p ) cin >> i;
    sort(all(p));
    p.resize(unique(all(p))-p.begin());
    n = (int)p.size();
    const int inf = 1e16+1;
    auto ok = [&](int w){
        for ( int i = 0; i <= n; i++ ){
            for ( int j = 0; j <= P; j++ ){
                dp[i][j] = inf;
            }
        }
        for ( int i = 0; i <= P; i++ ) dp[0][i] = 0;
        auto f = [&](int x){
            return lower_bound(all(p), x)-p.begin();
        };
        for ( int i = 1; i <= n; i++ ){
            for ( int j = 0; j <= P; j++ ){
                int val = f(p[i-1]-w*2+1);
                chmin(dp[i][j], dp[val][j]+1);
                if ( j ){
                    val = f(p[i-1]-w+1);
                    chmin(dp[i][j], dp[val][j-1]);
                }
            }
        }
        return dp[n][P] <= Q;
    };
    int l = 1, r = 1e9;
    while ( l < r ){
        int md = (l+r) >> 1;
        if ( ok(md) ) r = md;
        else l = md+1;
    }
    cout << l;

    cout << '\n';
}

Compilation message

watching.cpp: In function 'void IO(std::string)':
watching.cpp:11:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 | void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:11:70: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 | void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 724 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 7 ms 724 KB Output is correct
5 Correct 1 ms 724 KB Output is correct
6 Correct 6 ms 724 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 1 ms 724 KB Output is correct
9 Correct 1 ms 724 KB Output is correct
10 Correct 1 ms 712 KB Output is correct
11 Correct 4 ms 712 KB Output is correct
12 Correct 3 ms 724 KB Output is correct
13 Correct 1 ms 724 KB Output is correct
14 Correct 1 ms 712 KB Output is correct
15 Correct 1 ms 716 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 8532 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Execution timed out 1069 ms 31388 KB Time limit exceeded
4 Halted 0 ms 0 KB -