TIANKENG’s restaurant HDU

TIANKENG manages a restaurant after graduating from ZCMU, and tens of thousands of customers come to have meal because of its delicious dishes. Today n groups of customers come to enjoy their meal, and there are Xi persons in the ith group in sum. Assuming that each customer can own only one chair. Now we know the arriving time STi and departure time EDi of each group. Could you help TIANKENG calculate the minimum chairs he needs to prepare so that every customer can take a seat when arriving the restaurant?
Input
The first line contains a positive integer T(T<=100), standing for T test cases in all.

Each cases has a positive integer n(1<=n<=10000), which means n groups of customer. Then following n lines, each line there is a positive integer Xi(1<=Xi<=100), referring to the sum of the number of the ith group people, and the arriving time STi and departure time Edi(the time format is hh:mm, 0<=hh<24, 0<=mm<60), Given that the arriving time must be earlier than the departure time.

Pay attention that when a group of people arrive at the restaurant as soon as a group of people leaves from the restaurant, then the arriving group can be arranged to take their seats if the seats are enough.
Output
For each test case, output the minimum number of chair that TIANKENG needs to prepare.
Sample Input
2
2
6 08:00 09:00
5 08:59 09:59
2
6 08:00 09:00
5 09:00 10:00
Sample Output
11
6

//#include<map>
#include<queue>
#include<stack>
#include<vector>
#include<math.h>
#include<cstdio>
#include<sstream>
#include<numeric>//STL数值算法头文件
#include<stdlib.h>
#include<string.h>
#include<iostream>
#include<algorithm>
#include<functional>//模板类头文件
using namespace std;

const int INF=1e9+7;
const int maxn=11000;
typedef long long ll;

//暴力!!!
//首先,电脑读数的时候竟然是从第一个不是0的开始的！！！
//其次,这一道题用暴力,一天一共1440分钟,所以你把开始时间和结束时间
//化为分钟,然后在区间取x的最大值就是这一的答案

int a[maxn];

int main ()
{
    int t,n;
    int x,h,m;
    scanf("%d",&t);
    while (t--)
    {
        scanf("%d",&n);
        memset(a,0,sizeof (a));
        for(int i=0; i<n; i++)
        {
            scanf ("%d", &x);
            scanf ("%d:%d", &h, &m);
            a[h * 60 + m] += x;
            scanf ("%d:%d", &h, &m);
            a[h * 60 + m] -= x;
        }
        int sum = 0;
        int maxx = 0;
        for (int i = 0; i < maxn; i++)
        {
            sum += a[i];
            if (sum > maxx)
                maxx=sum;
        }
        printf("%d
",maxx);
    }
    return 0;
}