poj 1083 Moving Tables

#include <iostream>
#include <algorithm>
using namespace std;
struct node
{
int x,y;
bool operator<(const node& o)
{
return x<o.x;
}
}ans[300];
int main()
{
int t,n,i,s,tag[300];
cin>>t;
while(t--)
{
cin>>n;
int a,b;
for(i=0;i<n;++i)
{
cin>>a>>b;
if(a>b)
swap(a,b);
if(a%2==0)
a=a/2-1;
else
a=a/2;
if(b%2==0)
b=b/2-1;
else
b=b/2;
ans[i].x=a;ans[i].y=b;
}
sort(ans,ans+n);
memset(tag,0,sizeof(tag));
int r,c=0;
s=0;
while(c<n)
{
r=-1;
for(i=0;i<n&&c<n;++i)
{
if(tag[i]||ans[i].x<=r)
continue;
c++;
tag[i]=1;
r=ans[i].y;
}
s++;
}
cout<<10*s<<endl;
}
return 0;
}