Poj3264balanced lineup (Basic Line Segment tree)

Source: Internet
Author: User

Uses a one-dimensional array. (Because the one-dimensional number is a Complete Binary Tree, the time is slower than using the child node pointer to build the tree, but you can basically ignore =-=)

#include<iostream>#include<cstdio>#include<algorithm>using namespace std;const int INF = 0xffffff0;int minV=INF;int maxV=-INF;struct Node{    int L,R;    int minV,maxV;    int Mid()    {        return (L+R)/2;    }};Node tree[800010];void BuildTree(int root,int L,int R){    tree[root].L=L;    tree[root].R=R;    tree[root].maxV=-INF;    tree[root].minV=INF;    if(L!=R)    {        BuildTree(2*root+1,L,(L+R)/2);        BuildTree(2*root+2,1+(L+R)/2,R);    }}void Insert(int root, int i,int v){    if(tree[root].L==tree[root].R)    {        tree[root].maxV=tree[root].minV=v;        return;    }    tree[root].minV=min(tree[root].minV,v);    tree[root].maxV=max(tree[root].maxV,v);    if(i<=tree[root].Mid())    {        Insert(2*root+1,i,v);    }    else    {        Insert(2*root+2,i,v);    }}void Query(int root,int s,int e){    if(tree[root].minV>=minV&&tree[root].maxV<=maxV)    {        return;    }    if(tree[root].L==s&&tree[root].R==e)    {        minV=min(tree[root].minV,minV);        maxV=max(tree[root].maxV,maxV);        return;    }    if(e<=tree[root].Mid())    {        Query(1+root*2,s,e);    }    else if(s>tree[root].Mid())    {        Query(2+root*2,s,e);    }    else    {        Query(2*root+1,s,tree[root].Mid());        Query(2*root+2,tree[root].Mid()+1,e);    }}int main(){    int n,q,h;    int i;    //freopen("d:\\test.txt","r",stdin);    scanf("%d%d",&n,&q);    BuildTree(0,1,n);    for( i= 1; i <= n; i++ )    {        scanf("%d",&h);        Insert(0,i,h);    }    for( i= 0; i < q; i++ )    {        int s,e;        scanf("%d%d", &s,&e);        minV= INF;        maxV= -INF;        Query(0,s,e);        printf("%d\n",maxV-minV);    }    return 0;}


Poj3264balanced lineup (Basic Line Segment tree)

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.