ural 1019 Line Painting 线段树 区间染色

#include<cstdio>
#include<cstring>
#include<algorithm>
#define left l,m,x<<1
#define right m+1,r,x<<1|1
const int LMT=35005;
const int big=1000000000;
using namespace std;
int cov[LMT<<2],myx[LMT],cnt;
bool seg[LMT];
struct line
{
	int x1,x2;
	char c;
}e[LMT];
void init(void)
{
	memset(cov,-1,sizeof(cov));
}
void cut(int x)
{
	if(cov[x]!=-1)
	{
		cov[x<<1]=cov[x<<1|1]=cov[x];
		cov[x]=-1;
	}
}
void update(int op,int L,int R,int l,int r,int x)
{
	if(L<=l&&r<=R)
	{
		cov[x]=op;
		return;
	}
	cut(x);
	int m=(l+r)>>1;
	if(L<=m)update(op,L,R,left);
	if(R>m)update(op,L,R,right);
}
void query(int l,int r,int x)
{
	if(cov[x]!=-1)
	{
		int i=l;
		for(;i<=r;i++)seg[i]=cov[x];
		return;
	}
	if(l==r)return;
	cut(x);
	int m=(l+r)>>1;
	query(left);
	query(right);
}
int myfind(int x)
{
	int l=0,r=cnt-1,m;
	while(l<=r)
	{
		m=(l+r)>>1;
		if(myx[m]==x)return m;
		if(myx[m]>x)r=m-1;
		else l=m+1;
	}
	return -1;
}
int main(void)
{
	int n,i,t,j,leng=0,ansl,ansr,k;
	scanf("%d",&n);
	myx[cnt++]=0;
	myx[cnt++]=big;
	for(i=0;i<n;i++)
	{
		scanf("%d%d %c",&e[i].x1,&e[i].x2,&e[i].c);getchar();
		myx[cnt++]=e[i].x1;
		myx[cnt++]=e[i].x2;
	}
	t=1;
	for(i=1;i<cnt;i++)
		if(myx[i]!=myx[i-1])
			myx[t++]=myx[i];
    cnt=t;
	sort(myx,myx+cnt);
	t=cnt;
	for(i=1;i<t;i++)
		if(myx[i]-myx[i-1]>1)
		myx[cnt++]=myx[i-1]+1;
    sort(myx,myx+cnt);
	for(i=0;i<n;i++)
	{
		e[i].x1=myfind(e[i].x1);
		e[i].x2=myfind(e[i].x2);
		update(e[i].c=='b',e[i].x1,e[i].x2-1,0,cnt-1,1);
	}
	query(0,cnt-1,1);
	for( i=0;i<cnt;)
	{
			j=i;
			while(j<cnt&&seg[j]==seg[i])j++;
			if(j==cnt)k=big;
			else k=myx[j];
			if(0==seg[i]&&leng<k-myx[i])
			{
				leng=k-myx[i];
				ansl=myx[i];ansr=k;
			}
			i=j;
	}
	printf("%d %d\n",ansl,ansr);
	return 0;
}