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Submission #219253

# Submission time Handle Problem Language Result Execution time Memory
219253 2020-04-04T19:29:05 Z MKopchev Watching (JOI13_watching) C++14
0 / 100
 709 ms 33536 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);
    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:49:31: 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
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 67 ms 16640 KB Output is correct
2 Correct 64 ms 16640 KB Output is correct
3 Correct 68 ms 16640 KB Output is correct
4 Runtime error 30 ms 33536 KB Execution killed with signal 11 (could be triggered by violating memory limits)
5 Halted 0 ms 0 KB -

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 16760 KB Output is correct
2 Correct 64 ms 16640 KB Output is correct
3 Correct 709 ms 16888 KB Output is correct
4 Runtime error 33 ms 33536 KB Execution killed with signal 11 (could be triggered by violating memory limits)
5 Halted 0 ms 0 KB -