16.7.7 T2:Window

来源:互联网 发布:linux pcb 编辑:程序博客网 时间:2024/06/05 11:42

Description

  给你一个长度为N的数组,一个长为K的滑动的窗体从最左移至最右端,你只能见到窗口的K个数,每次窗体向右移动一位,如下表:
  
  
  你的任务是找出窗口在各位置时的max value,min value.

Input

  第1行n,k,第2行为长度为n的数组

Output

  2行,第1行每个位置的min value,第2行每个位置的max value

Sample Input

8 3

1 3 -1 -3 5 3 6 7

Sample Output

-1 -3 -3 -3 3 3

3 3 5 5 6 7

Data Constraint

Hint

数据范围:
  20%: n<=500; 50%: n<=100000;
  100%: n<=1000000
  
  **因为这道题目数据大,而且一次要维护那么多“区间”,于是第一时间想到时间复杂度为O(n log n)的线段树,之前也做过类似的题目,像最大值就是这个的一个缩影:https://jzoj.net/senior/#main/show/1959。
  于是,我像做最大值一样维护区间最小值,然后维护最大值,但只能拿90分,让我们来看看原因:n是极端的时候,时间复杂度约为12000000,再加些杂七杂八的都要>25000000,所以呢,两个合并一下,应该可以减少一些复杂度。**
 

#include<cstdio>#include<iostream>#include<cstring>using namespace std;const int maxn=1000000+500;int   n,k;int   a[maxn];int treemax[maxn*4];int  treemin[maxn*4];int ans1,ans2;int help[maxn][3];inline void buildtree(int  x,int  left,int  right){    if(left==right) treemax[x]=treemin[x]=a[left];    else    {        int  mid=(left+right)/2;        buildtree(x*2,left,mid);        buildtree(x*2+1,mid+1,right);        treemax[x]=max(treemax[x*2],treemax[x*2+1]);        treemin[x]=min(treemin[x*2],treemin[x*2+1]);    }       }/*inline void buildtreemin(int x,int  left,int  right){    if(left==right) treemin[x]=a[left];    else    {        int  mid=(left+right)/2;        buildtreemin(x*2,left,mid);        buildtreemin(x*2+1,mid+1,right);        treemin[x]=min(treemin[x*2],treemin[x*2+1]);    }}*//*void change(int x,int left,int right,int pd,int count){     if(left==right) tree[x]=count;     else     {         int mid=(left+right)/2;          if(pd<=mid) change(x*2,left,mid,pd,count);          else change(2*x+1,mid+1,right,pd,count);          tree[x]=max(tree[x*2],tree[x*2+1]);     }}*/inline void treefind(int  x,int  start,int end,int  left,int  right){     if(start==left && end==right) {ans1=min(ans1,treemin[x]);ans2=max(ans2,treemax[x]);}     else     {      int  mid=(start+end)/2;      if(right<=mid)  treefind(x*2,start,mid,left,right);      else if(left>mid) treefind(x*2+1,mid+1,end,left,right);      else      {        treefind(x*2,start,mid,left,mid);        treefind(x*2+1,mid+1,end,mid+1,right);      }     }}/*inline void treefindmin(int  x,int  start,int  end,int  left,int  right){    if(start==left && end==right)  {ans=min(ans,treemin[x]);    else    {        int  mid=(start+end)/2;        if(right<=mid) treefindmin(x*2,start,mid,left,right);        else if(left>mid) treefindmin(x*2+1,mid+1,end,left,right);        else        {            treefindmin(x*2,start,mid,left,mid);            treefindmin(x*2+1,mid+1,end,mid+1,right);        }    }}*//*inline void treefind(int  x,int  start,int end,int  left,int  right){     if(start==left && end==right)      {        ansmax[top]=max(ansmax[top],treemax[x]);        ansmin[top]=min(ansmin[top],treemin[x]);     }     else     {      int  mid=(start+end)/2;      if(right<=mid)   treefind(x*2,start,mid,left,right);      else if(left>mid) treefind(x*2+1,mid+1,end,left,right);      else      {        treefind(x*2,start,mid,left,mid);        treefind(x*2+1,mid+1,end,mid+1,right);      }     }}*/int main(){    freopen("2.in","r",stdin);    scanf("%d %d",&n,&k);    for(int  i=1;i<=n;i++) scanf("%d",&a[i]);    buildtree(1,1,n);    int x,y;    for(int  i=1,j=k;i<=n-k+1,j<=n;i++,j++)     {      ans1=0x7fffffff;      ans2=0;      treefind(1,1,n,i,j);      help[i][1]=ans1;      help[i][2]=ans2;    }    for(int  i=1;i<=n-k+1;i++)     {      if(i!=n-k+1) printf("%d ",help[i][1]);      else printf("%d\n",help[i][1]);    }    for(int  i=1;i<=n-k+1;i++)     {      if(i!=n-k+1) printf("%d ",help[i][2]);      else printf("%d\n",help[i][2]);    }    return 0;}
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