Submission #557408

#	Time	Username	Problem	Language	Result	Execution time	Memory
557408		hibiki	Martian DNA (BOI18_dna)	C++11	100 / 100	125 ms	19608 KiB

dna

#include<bits/stdc++.h>
using namespace std;

#define PB push_back
#define F first
#define S second

int n,k,r;
int arr[200200],req[200200],idx[200200];
vector<int> ty[200200];
set<int> s;

int main()
{
    memset(idx,-1,sizeof(idx));
    scanf("%d %d %d",&n,&k,&r);
    for(int i=0;i<n;i++)
    {
        scanf("%d",&arr[i]);
        ty[arr[i]].PB(i);
    }
    for(int i=0;i<r;i++)
    {
        int a;
        scanf("%d",&a);
        scanf("%d",&req[a]);
    }
    int ans=1e9;
    for(int i=0;i<n;i++)
    {
        if(req[arr[i]]==0)continue;

        int prev=idx[arr[i]];
        int nw=idx[arr[i]]+1;
        int prev_req=max(-1,prev-req[arr[i]]+1);
        int nw_req=max(-1,nw-req[arr[i]]+1);

        if(prev_req==-1)
            s.erase(prev_req);
        else
            s.erase(ty[arr[i]][prev_req]);
        if(nw_req==-1)
            s.insert(nw_req);
        else
            s.insert(ty[arr[i]][nw_req]);
        if(s.size() == r && *s.begin() != -1 )
            ans=min(ans,i - *s.begin() + 1 );

        idx[arr[i]]++;
    }
    if(ans==1e9)
        printf("impossible\n");
    else
        printf("%d\n",ans);
    return 0;
}

Compilation message (stderr)

dna.cpp: In function 'int main()':
dna.cpp:46:21: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   46 |         if(s.size() == r && *s.begin() != -1 )
      |            ~~~~~~~~~^~~~
dna.cpp:16:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     scanf("%d %d %d",&n,&k,&r);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~
dna.cpp:19:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         scanf("%d",&arr[i]);
      |         ~~~~~^~~~~~~~~~~~~~
dna.cpp:25:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |         scanf("%d",&a);
      |         ~~~~~^~~~~~~~~
dna.cpp:26:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |         scanf("%d",&req[a]);
      |         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 16 / 16
• Subtask 2: 24 / 24
• Subtask 3: 28 / 28
• Subtask 4: 32 / 32