POJ 1083

#include<iostream>
#include<stdio.h>
#include<algorithm>
#define MAXN 400
using namespace std;

int a[MAXN];
void op(int & a);
int main()
{
    //freopen("acm.acm","r",stdin);
    int time;
    int num;
    int i;
    int j;
    int begin;
    int end;
    memset(a,0,sizeof(a));
    cin>>time;
    while(time --)
    {
        memset(a,0,sizeof(a));
        cin>>num;
        for(i = 0; i < num; ++ i)
        {
            cin>>begin;
            cin>>end;
            if(begin > end)
                iter_swap(&begin,&end);
            begin = (begin-1)/2;
            end = (end-1)/2;
            for_each(a+begin,a+end+1,op);
        }
        cout<< 10*(*max_element(a,a+MAXN))<<endl;
    }
}
void op(int & a)
{
    a += 1;
}