oj.uz

Submission #106859

# Submission time Handle Problem Language Result Execution time Memory
106859 2019-04-20T18:53:23 Z someone_aa Watching (JOI13_watching) C++17
100 / 100
 589 ms 17008 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;

    int lst = 1, lst2=1;
    for(int i=1;i<=v.size();i++) {
        //cout<<i<<":\n";

        while(v[i-1] - v[lst-1] >= x && lst < i) lst++;
        while(v[i-1] - v[lst2-1] >= 2*x && lst2 < i) lst2++;

        for(int j=0;j<=q;j++) {

            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:23:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=1;i<=v.size();i++) {
                 ~^~~~~~~~~~
watching.cpp:43:18: 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 2 ms 256 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 3 ms 768 KB Output is correct
5 Correct 5 ms 768 KB Output is correct
6 Correct 3 ms 768 KB Output is correct
7 Correct 3 ms 768 KB Output is correct
8 Correct 3 ms 768 KB Output is correct
9 Correct 3 ms 768 KB Output is correct
10 Correct 3 ms 768 KB Output is correct
11 Correct 3 ms 768 KB Output is correct
12 Correct 4 ms 768 KB Output is correct
13 Correct 4 ms 896 KB Output is correct
14 Correct 3 ms 768 KB Output is correct
15 Correct 4 ms 768 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 107 ms 16912 KB Output is correct
2 Correct 3 ms 256 KB Output is correct
3 Correct 497 ms 16892 KB Output is correct
4 Correct 119 ms 16760 KB Output is correct
5 Correct 554 ms 16888 KB Output is correct
6 Correct 512 ms 16932 KB Output is correct
7 Correct 95 ms 16896 KB Output is correct
8 Correct 314 ms 16888 KB Output is correct
9 Correct 138 ms 16768 KB Output is correct
10 Correct 132 ms 16888 KB Output is correct
11 Correct 589 ms 16900 KB Output is correct
12 Correct 339 ms 17008 KB Output is correct
13 Correct 112 ms 16868 KB Output is correct
14 Correct 98 ms 16936 KB Output is correct
15 Correct 99 ms 16940 KB Output is correct