Submission #529173

#	Time	Username	Problem	Language	Result	Execution time	Memory
529173		ToroTN	Martian DNA (BOI18_dna)	C++14	100 / 100	63 ms	4568 KiB

dna

#include<bits/stdc++.h>
using namespace std;
int n,m,t,want[200005],num1,num2,a[200005],st,md,ed,hsh[200005],cnt,type,kanttee;
int main()
{
    scanf("%d%d%d",&n,&m,&t);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&a[i]);
        a[i]+=1;
    }
    for(int i=1;i<=t;i++)
    {
        scanf("%d%d",&num1,&num2);
        want[num1+1]=max(want[num1+1],num2);
    }
    st=1;
    ed=n;
    while(ed>=st)
    {
        type=-1;
        md=(st+ed)/2;
        //printf("%d %d %d\n",st,md,ed);
        kanttee=m-t;
        memset(hsh,0,sizeof hsh);
        for(int i=1;i<=md;i++)
        {
            ++hsh[a[i]];
            if(hsh[a[i]]==want[a[i]])
            {
                ++kanttee;
            }
        }
        //printf("1 %d\n",kanttee);
        if(kanttee==m)
        {
            type=0;
        }
        for(int i=2;i<=n-md+1;i++)
        {
            --hsh[a[i-1]];
            if(hsh[a[i-1]]==want[a[i-1]]-1)
            {
                --kanttee;
            }
            ++hsh[a[i+md-1]];
            if(hsh[a[i+md-1]]==want[a[i+md-1]])
            {
                ++kanttee;
            }
            //printf("%d %d\n",i,kanttee);
            if(kanttee==m)
            {
                type=0;
            }
        }
        if(type==0)
        {
            ed=md-1;
        }else
        {
            st=md+1;
        }
    }
    if(st==n+1)
    {
        printf("impossible\n");
    }else
    {
        printf("%d\n",st);
    }
}

Compilation message (stderr)

dna.cpp: In function 'int main()':
dna.cpp:6:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    6 |     scanf("%d%d%d",&n,&m,&t);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
dna.cpp:9:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |         scanf("%d",&a[i]);
      |         ~~~~~^~~~~~~~~~~~
dna.cpp:14:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |         scanf("%d%d",&num1,&num2);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~

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