pku2823【单调队列】

pku2823【单调队列】

题目链接： http://acm.pku.edu.cn/JudgeOnline/problem?id=2823

#include < iostream >
using   namespace  std;
int  n,k;
int  a[ 1000002 ];
void  puts_val( int  flag)
{
     int q[1000002];
     int i,head=0,tail=0;
     if(flag)
     {
         for(i=1;i<=k-1;i++)
         {
             while(head<tail&&a[q[tail-1]]<a[i]) tail--;
             q[tail++]=i;
         }
         for(i=k;i<=n;i++)
         {
             while(head<tail&&a[q[tail-1]]<a[i]) tail--;
             q[tail++]=i;
             while(head<tail&&i-q[head]>=k) head++;
             if(i!=n) printf("%d ",a[q[head]]);
             else printf("%d\n",a[q[head]]);
         }  
     }
     else
     {
         for(i=1;i<=k-1;i++)
         {
             while(head<tail&&a[q[tail-1]]>a[i]) tail--;
             q[tail++]=i;             
         }
         for(i=k;i<=n;i++)
         {
              while(head<tail&&a[q[tail-1]]>a[i]) tail--;
              q[tail++]=i;
              while(head<tail&&i-q[head]>=k)  head++;
              if(i!=n) printf("%d ",a[q[head]]);
              else printf("%d\n",a[q[head]]);
         }
     }
}
int  main()
{
    scanf("%d%d",&n,&k);
    for(int i=1;i<=n;i++)
    scanf("%d",&a[i]);
    puts_val(0);
    puts_val(1);
    //system("pause");
    return 0;
}