oj.uz

Submission #219254

# Submission time Handle Problem Language Result Execution time Memory
219254 2020-04-04T19:30:35 Z MKopchev Watching (JOI13_watching) C++14
50 / 100
 1000 ms 16888 KB 
#include<bits/stdc++.h>
using namespace std;
const int nmax=2e3+42;
int n,p,q,inp[nmax];

int would_go_small[nmax],would_go_big[nmax];

int dp[nmax][nmax];

int rec(int p_now,int q_now)
{
    if(p_now==0&&q_now==0)return 1;
    if(dp[p_now][q_now]!=-1)return dp[p_now][q_now];

    int ret=0,current;
    if(p_now)
    {
        current=would_go_small[rec(p_now-1,q_now)];
        ret=max(ret,current);
    }

    if(q_now)
    {
        current=would_go_big[rec(p_now,q_now-1)];
        ret=max(ret,current);
    }

    dp[p_now][q_now]=ret;
    return ret;
}
bool can(int w)
{
    for(int i=1;i<=n;i++)
    {
        would_go_small[i]=lower_bound(inp+1,inp+n+1,inp[i]+w)-inp;
        would_go_big[i]=lower_bound(inp+1,inp+n+1,inp[i]+2*w)-inp;
        //cout<<i<<" -> "<<would_go_small[i]<<" "<<would_go_big[i]<<endl;
    }

    would_go_big[n+1]=n+1;
    would_go_small[n+1]=n+1;

    memset(dp,-1,sizeof(dp));
    return rec(p,q)>n;
}
int main()
{
    scanf("%i%i%i",&n,&p,&q);

    p=min(p,n);
    q=min(q,n);

    for(int i=1;i<=n;i++)scanf("%i",&inp[i]);
    sort(inp+1,inp+n+1);

    int ok=1e9/3+1,not_ok=0;
    while(ok-not_ok>1)
    {
        int av=(ok+not_ok)/2;
        if(can(av))ok=av;
        else not_ok=av;
    }
    printf("%i\n",ok);
    return 0;
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:48:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%i%i%i",&n,&p,&q);
     ~~~~~^~~~~~~~~~~~~~~~~~~
watching.cpp:53:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i=1;i<=n;i++)scanf("%i",&inp[i]);
                          ~~~~~^~~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 16640 KB Output is correct
2 Correct 67 ms 16640 KB Output is correct
3 Correct 71 ms 16640 KB Output is correct
4 Correct 65 ms 16640 KB Output is correct
5 Correct 65 ms 16640 KB Output is correct
6 Correct 68 ms 16640 KB Output is correct
7 Correct 67 ms 16640 KB Output is correct
8 Correct 66 ms 16640 KB Output is correct
9 Correct 64 ms 16640 KB Output is correct
10 Correct 65 ms 16640 KB Output is correct
11 Correct 66 ms 16640 KB Output is correct
12 Correct 72 ms 16640 KB Output is correct
13 Correct 78 ms 16696 KB Output is correct
14 Correct 65 ms 16640 KB Output is correct
15 Correct 67 ms 16640 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 16692 KB Output is correct
2 Correct 69 ms 16692 KB Output is correct
3 Correct 653 ms 16792 KB Output is correct
4 Correct 112 ms 16768 KB Output is correct
5 Correct 110 ms 16768 KB Output is correct
6 Execution timed out 1042 ms 16888 KB Time limit exceeded
7 Halted 0 ms 0 KB -