ural 1019 Line Painting

http://acm.timus.ru/problem.aspx?space=1&num=1019

#include <cstdio>
#include <cstring>
#include <algorithm>
#define maxn 200100
using namespace std;

struct node
{
    int r,l,co;
}tree[maxn*4];
int co[maxn],l[maxn],r[maxn];
struct node1
{
    int x,y,co;
}p[maxn*4];

void build(int i,int l,int r)
{
    tree[i].l=l;tree[i].r=r;
    tree[i].co=1;
    if(l==r-1) return ;
    int mid=(l+r)>>1;
    build(i<<1,l,mid);
    build(i<<1|1,mid,r);
}

void update(int i,int l,int r,int co)
{
    if(tree[i].l==l&&tree[i].r==r)
    {
        tree[i].co=co;
        return ;
    }
    if(tree[i].co>=0&&tree[i].co!=co)
    {
        tree[i<<1].co=tree[i<<1|1].co=tree[i].co;
        tree[i].co=-1;
    }
    int mid=(tree[i].l+tree[i].r)>>1;
    if(r<=mid)
    {
        update(i<<1,l,r,co);
    }
    else if(l>=mid)
    {
        update(i<<1|1,l,r,co);
    }
    else
    {
        update(i<<1,l,mid,co);
        update(i<<1|1,mid,r,co);
    }
}

void search1(int i,int l,int r)
{
    if(tree[i].co>=0)
    {
        for(int j=tree[i].l; j<tree[i].r; j++)
        {
            co[j]=tree[i].co;
        }
        return ;
    }
    int mid=(tree[i].l+tree[i].r)>>1;
    if(r<=mid)
    {
        search1(i<<1,l,r);
    }
    else if(l>=mid)
    {
        search1(i<<1|1,l,r);
    }
    else
    {
        search1(i<<1,l,mid);
        search1(i<<1|1,mid,r);
    }
}

int bs(int key,int li,int ri)
{
    int low=li,high=ri-1;
    while(low<=high)
    {
        int mid=(low+high)>>1;
        if(l[mid]==key) return mid;
        else if(l[mid]>key)
           high=mid-1;
        else
           low=mid+1;
    }
}

int main()
{
    int n;
    char ch;
    scanf("%d",&n);
    int cnt=0;
    for(int i=0; i<=maxn; i++)
    {
        co[i]=1;
    }
    p[0].x=0;p[0].y=1000000000;
    l[cnt++]=p[0].x; l[cnt++]=p[0].y;
    for(int i=0; i<n; i++)
    {
        scanf("%d%d %c",&p[i].x,&p[i].y,&ch);
        l[cnt++]=p[i].x; l[cnt++]=p[i].y;
        if(ch=='w')
        {
            p[i].co=1;
        }
        getchar();
    }
    sort(l,l+cnt);
    int t=1;
    for(int i=1; i<cnt; i++)
    {
        if(l[i]!=l[i-1]) l[t++]=l[i];
    }
    build(1,0,t);
    for(int i=0; i<n; i++)
    {
        int li=bs(p[i].x,0,t);
        int ri=bs(p[i].y,0,t);
        //printf("%d %d\n",li,ri);
        update(1,li,ri,p[i].co);
    }
    search1(1,0,t);
    int s=0,e=0,si,ei;
    co[t]=0;
    l[t]=1000000000;
    for(int i=0; i<t; i++)
    {
        si=l[i];
        while(co[i]==1)
        i++;
        ei=l[i];
        if(ei-si>e-s)
        {
            e=ei;
            s=si;
        }
    }
    printf("%d %d\n",s,e);
    return 0;
}