Sliding Window

poj2823:http://poj.org/problem?id=2823

题意：给出一个序列，要求得到所有长度为k的连续子序列的最大和最小值。
题解：直接上线段树

 #include<iostream>
 #include<cstring>
 #include<cstdio>
 #include<algorithm>
 using namespace std;
 const int maxn=;
 int n,k,s;
 struct  Node{
     int left;
     int right;
     int minn;
     int maxn;
 }node[*maxn];
 void build(int l,int r,int idx){
     node[idx].left=l;
     node[idx].right=r;
     if(l==r){
         scanf("%d",&s);
         node[idx].minn=s;
         node[idx].maxn=s;
         return;
     }
     int mid=(l+r)/;
     build(l,mid,idx*);
     build(mid+,r,idx*+);
     node[idx].maxn=max(node[idx*].maxn,node[idx*+].maxn);
     node[idx].minn=min(node[idx*].minn,node[idx*+].minn);
 }
 int queryminn(int s,int t,int idx){
     if(node[idx].left==s&&node[idx].right==t){
         return node[idx].minn;
     }
     int mid=(node[idx].left+node[idx].right)/;
     if(mid>=t)return queryminn(s,t,idx*);//范围只能这么写，否则会出错
     else if(mid<s)return queryminn(s,t,idx*+);
     else
       return min(queryminn(s,mid,idx*),queryminn(mid+,t,idx*+));
 }
 int querymaxnn(int s,int t,int idx){
     if(node[idx].left==s&&node[idx].right==t){
         return node[idx].maxn;
     }
     int mid=(node[idx].left+node[idx].right)/;
     if(mid>=t)return querymaxnn(s,t,idx*);
     else if(mid<s)return querymaxnn(s,t,idx*+);
     else
       return max(querymaxnn(s,mid,idx*),querymaxnn(mid+,t,idx*+));
 }
 int main(){
     while(~scanf("%d%d",&n,&k)){
         build(,n,);
         for(int i=;i+k<=n+;i++){
             printf("%d ",queryminn(i,k+i-,));
         }
         printf("\n");
         for(int i=;i+k<=n+;i++){
             printf("%d ",querymaxnn(i,k+i-,));
         }
         printf("\n");
     }
 }