oj.uz

Submission #563386

# Submission time Handle Problem Language Result Execution time Memory
563386 2022-05-17T05:31:07 Z hibiki Watching (JOI13_watching) C++11
100 / 100
 268 ms 16016 KB 
#include<bits/stdc++.h>
using namespace std;

#define pb push_back
#define f first
#define s second

int n,p,q,dp[2005][2005];
vector<int> v;

int main()
{
    scanf("%d %d %d",&n,&p,&q);
    int lst = -1;
    for(int i = 0; i < n; i++)
    {
        int a;
        scanf("%d",&a);
        v.pb(a);
    }
    if(p + q >= n)
    {
        printf("1\n");
        return 0;
    }
    sort(v.begin(),v.end());
    int l = 1, r = 1e9 + 5;
    while(l <= r)
    {
        int mid = (l + r) / 2;
        if(l == r)
        {
            printf("%d\n",l);
            return 0;
        }
        for(int i = 0; i < n; i++)
            for(int j = 0; j <= p; j++)
                dp[i][j] = 1e9;
        for(int i = 0; i < n; i++)
        {
            int po = v[i];
            // use p
            int p_po = upper_bound(v.begin(),v.end(),po - mid) - v.begin() - 1;
            if(p_po == -1)
                dp[i][1] = 0;
            else
                for(int j = 1; j <= p; j++)
                {
                    dp[i][j] = min(dp[i][j],dp[p_po][j - 1]);
                }
            // use q
            p_po = upper_bound(v.begin(),v.end(),po - mid * 2) - v.begin() - 1;
            if(p_po == -1)
                dp[i][0] = 1;
            else
                for(int j = 0; j <= p; j++)
                {
                    dp[i][j] = min(dp[i][j],dp[p_po][j] + 1);
                }
        }
        bool chk = false;
        for(int i = 0; i <= p; i++)
            if(dp[n - 1][i] <= q)
            {
                chk = true;
                break;
            }
        if(chk)
            r = mid;
        else
            l = mid + 1;
    }
    return 0;
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:14:9: warning: unused variable 'lst' [-Wunused-variable]
   14 |     int lst = -1;
      |         ^~~
watching.cpp:13:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     scanf("%d %d %d",&n,&p,&q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~
watching.cpp:18:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |         scanf("%d",&a);
      |         ~~~~~^~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 596 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 1 ms 308 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 692 KB Output is correct
8 Correct 1 ms 688 KB Output is correct
9 Correct 1 ms 596 KB Output is correct
10 Correct 1 ms 596 KB Output is correct
11 Correct 1 ms 724 KB Output is correct
12 Correct 1 ms 724 KB Output is correct
13 Correct 1 ms 696 KB Output is correct
14 Correct 1 ms 596 KB Output is correct
15 Correct 1 ms 596 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 8276 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 316 KB Output is correct
7 Correct 9 ms 8404 KB Output is correct
8 Correct 27 ms 9300 KB Output is correct
9 Correct 120 ms 14224 KB Output is correct
10 Correct 268 ms 16016 KB Output is correct
11 Correct 21 ms 9044 KB Output is correct
12 Correct 155 ms 16000 KB Output is correct
13 Correct 10 ms 8380 KB Output is correct
14 Correct 13 ms 8500 KB Output is correct
15 Correct 11 ms 8488 KB Output is correct