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;
}