oj.uz

Submission #106856

# Submission time Handle Problem Language Result Execution time Memory
106856 2019-04-20T18:48:59 Z someone_aa Watching (JOI13_watching) C++17
50 / 100
 1000 ms 16896 KB 
#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
using namespace std;
const int maxn = 2100;
int n, p, q;
set<int>st;
vector<int>v;
int dp[maxn][maxn];

bool check(ll x) {
    for(int i=0;i<=v.size();i++) {
        for(int j=0;j<=v.size();j++) {
            dp[i][j] = 10000000;
        }
    }
    dp[0][0] = 0;

    int result = INT_MAX;
    for(int i=1;i<=v.size();i++) {
        //cout<<i<<":\n";
        for(int j=0;j<=q;j++) {

            int lst = 0, lst2=0;

            for(int d=1;d<=i;d++) {
                if(lst == 0 && v[i-1] - v[d-1] < x) lst = d;
                if(lst2 == 0 && v[i-1] - v[d-1] < 2*x) lst2 = d;
            }

            if(v[i-1] - v[lst-1] < x) {
                dp[i][j] = min(dp[i][j], dp[lst-1][j]+1);
                if(j-1>=0) {
                    dp[i][j] = min(dp[i][j], dp[lst-1][j-1]);
                }
            }

            if(v[i-1] - v[lst2-1] < 2*x && j>=1) {
                dp[i][j] = min(dp[i][j], dp[lst2-1][j-1]);
            }

            //cout<<j<<": "<<dp[i][j]<<"\n";
            if(i == v.size()) {
                result = min(result, dp[i][j]);
            }
        }
    }
    return result <= p;
}

int main() {
    cin>>n>>p>>q;

    int x;
    for(int i=1;i<=n;i++) {
        cin>>x;
        st.insert(x);
    }

    for(int i:st) {
        v.pb(i);
    }
    q = min(q, int(v.size()));


    ll l = 0LL, r = 1LL * 1e9;
    ll result = LLONG_MAX;
    while(l < r) {
        ll mid = (l + r) / 2;

        if(check(mid)) {
            result = min(result, mid);
            r = mid;
        }
        else {
            l = mid + 1;
        }
    }
    cout<<result<<"\n";
    return 0;
}

Compilation message

watching.cpp: In function 'bool check(long long int)':
watching.cpp:13:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<=v.size();i++) {
                 ~^~~~~~~~~~
watching.cpp:14:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0;j<=v.size();j++) {
                     ~^~~~~~~~~~
watching.cpp:21:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=1;i<=v.size();i++) {
                 ~^~~~~~~~~~
watching.cpp:44:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if(i == v.size()) {
                ~~^~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 768 KB Output is correct
2 Correct 3 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 5 ms 768 KB Output is correct
5 Correct 29 ms 768 KB Output is correct
6 Correct 29 ms 768 KB Output is correct
7 Correct 4 ms 768 KB Output is correct
8 Correct 7 ms 768 KB Output is correct
9 Correct 4 ms 768 KB Output is correct
10 Correct 22 ms 768 KB Output is correct
11 Correct 10 ms 768 KB Output is correct
12 Correct 20 ms 896 KB Output is correct
13 Correct 8 ms 768 KB Output is correct
14 Correct 7 ms 816 KB Output is correct
15 Correct 4 ms 768 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 251 ms 16896 KB Output is correct
2 Correct 2 ms 256 KB Output is correct
3 Execution timed out 1060 ms 16768 KB Time limit exceeded
4 Halted 0 ms 0 KB -