【BZOJ2823】Sliding Window

经典单调队列

 1 #include<cstdio>
 2 #include<cstring>
 3 using namespace std;
 4 const int N=1000010;
 5 int maxq[N],minq[N],a[N],ans1[N],ans2[N],lmax,lmin,rmax,rmin;
 6 int main(){
 7     int n,k;
 8     lmax=lmin=rmax=rmin=0;
 9     scanf("%d %d",&n,&k);
10     for (int i=1;i<=n;i++)
11         scanf("%d",&a[i]);
12     for (int i=1;i<=n;i++){
13         while (lmax<=rmax&&maxq[lmax]<=i-k) lmax++;
14         while (lmin<=rmin&&minq[lmin]<=i-k) lmin++;
15         while (rmax>=lmax&&a[maxq[rmax]]<a[i]) rmax--;
16         maxq[++rmax]=i;
17         while (rmin>=lmin&&a[minq[rmin]]>a[i]) rmin--;
18         minq[++rmin]=i;
19         ans1[i]=a[minq[lmin]];
20         ans2[i]=a[maxq[lmax]];
21     }
22     for (int i=k;i<=n;i++)
23         printf("%d ",ans1[i]);
24     printf("\n");
25     for (int i=k;i<=n;i++)
26         printf("%d ",ans2[i]);
27     return 0;
28 }

STD