hdu 1828 线段树+扫描线

矩形周长和~

#include 
#include 
#include 
#include 
#define lson pos<<1
#define rson pos<<1|1
using namespace std;
const int MAXN=30000;
struct line
{
    int l,r,h,f;
    line(int a=0,int b=0,int c=0,int d=0):l(a),r(b),h(c),f(d){}
};
line a[MAXN];
bool cmp(const line & lhs, const line &rhs)
{
    return lhs.h>1;
    }
};
node tree[MAXN*4];
void build(int l,int r,int pos)
{
    tree[pos].l=l;
    tree[pos].r=r;
    if(l==r)
    {
        tree[pos].cover=0;
        tree[pos].sum=0;
        tree[pos].lbd=tree[pos].rbd=0;
        tree[pos].numline=0;
        return ;
    }
    int mid=tree[pos].mid();
    build(l,mid,lson);
    build(mid+1,r,rson);
    tree[pos].sum=0;
    tree[pos].cover=0;
    tree[pos].lbd=tree[pos].rbd=0;
    tree[pos].numline=0;
}
int abs(int a)
{
    return a>0?a:-a;
}
void pushup(int pos)
{
    if(tree[pos].cover)
    {
        tree[pos].lbd=tree[pos].rbd=1;
        tree[pos].numline=2;
        tree[pos].sum=tree[pos].r-tree[pos].l+1;
    }
    else if(tree[pos].l==tree[pos].r)
        tree[pos].lbd=tree[pos].rbd=tree[pos].numline=tree[pos].sum=0;
    else
    {
        tree[pos].lbd=tree[lson].lbd;
        tree[pos].rbd=tree[rson].rbd;
        tree[pos].numline=tree[lson].numline+tree[rson].numline;
        if(tree[lson].rbd&&tree[rson].lbd)
            tree[pos].numline-=2;

        tree[pos].sum=tree[lson].sum+tree[rson].sum;
    }
}
void update(int l,int r,int f,int pos)
{
    if(l==tree[pos].l&&r==tree[pos].r)
    {
        tree[pos].cover+=f;
        pushup(pos);
        return ;
    }
    int mid=tree[pos].mid();
    if(r<=mid)
        update(l,r,f,lson);
    else if(l>mid)
        update(l,r,f,rson);
    else
    {
        update(l,mid,f,lson);
        update(mid+1,r,f,rson);
    }
    pushup(pos);
}
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        int i;
        int k=0;
        memset(a,0,sizeof(a));
        for(i=0;i