OJ-Problems-Source/HDOJ/5124_autoAC.cpp
2016-09-10 11:37:56 +08:00

113 lines
2.9 KiB
C++

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<set>
using namespace std;
struct line{
int l,r;
};
bool operator < (const line &a,const line &b)
{
if(a.r<b.r)return 1;
if(a.r==b.r){
if(a.l<b.l)return 1;
}
return 0;
}
line L[100005];
int pos[200005];
int d[400005];
int maxv[400005];
int yl,yr;
void maintain(int o,int l,int r)
{
int lc=o*2;
int rc=o*2+1;
if(r>l){
maxv[o]=max(maxv[lc],maxv[rc]);
}else maxv[o]=0;
maxv[o]+=d[o];
}
void update(int o,int l,int r)
{
int lc=o*2;
int rc=o*2+1;
if(yl<=l&&yr>=r){
d[o]++;
} else {
int mid=l+((r-l)>>1);
if(yl<=mid)update(lc,l,mid);
if(yr>mid)update(rc,mid+1,r);
}
maintain(o,l,r);
}
int query(int o,int l,int r,int add)
{
if(yl<=l&&yr>=r){
return maxv[o]+add;
} else {
int m=l+((r-l)>>1);
int ret=-1;
if(yl<=m)ret=max(ret,query(o*2 , l , m , add + d[o] ) );
if(yr>m)ret=max(ret , query(o*2+1 , m+1 , r , add+d[o]));
return ret;
}
}
int bisearch(int x,int tot)
{
int le=0;
int ri=tot-1;
while(le<ri){
int mid=(le+ri)>>1;
if(pos[mid]==x)return mid;
if(pos[mid]>x)ri=mid-1;
else {
le=mid+1;
}
}
return le;
}
int main()
{
int T;
scanf("%d",&T);
while(T--){
int n;
scanf("%d",&n);
int tot=0;
set<int> s;
s.clear();
for(int i=0;i<n;++i){
scanf("%d%d",&L[i].l,&L[i].r);
if(s.find(L[i].l)==s.end()){
s.insert(L[i].l);
pos[tot++]=L[i].l;
}
if(s.find(L[i].r)==s.end()){
s.insert(L[i].r);
pos[tot++]=L[i].r;
}
}
sort(pos,pos+tot);
for(int i=0;i<=tot*4;++i){
d[i]=0;
maxv[i]=0;
}
int ans=0;
for(int i=0;i<n;++i){
int le=bisearch(L[i].l,tot);
int ri=bisearch(L[i].r,tot);
le++;
ri++;
yl=le;
yr=ri;
update(1,1,tot);
}
yl=1;yr=tot;
ans=query(1,1,tot,0);
printf("%d\n",ans);
}
return 0;
}