11136-Hoax or what

Each Mal-Wart supermarket has prepared a promotion scheme run by the following rules:

• A client who wants to participate in the promotion (aka a sucker) must write down their phone number on the bill of their purchase and put the bill into a special urn.
• Two bills are selected from the urn at the end of each day: first the highest bill is selected and then the lowest bill is selected. The client who paid the largest bill receives a monetary prize equal to the difference between his bill and the lowest bill of the day.
• Both selected bills are not returned to the urn while all the remaining ones are kept in the urn for the next day.
• Mal-Wart has many clients such that at the end of each day there are at least two bills in the urn.
• It is quite obvious why Mal-Wart is doing this: they sell crappy products which break quickly and irreparably. They give a short-term warranty on their products but in order to obtain a warranty replacement you need the bill of sale. So if you are gullible enough to participate in the promotion you will regret it.

Your task is to write a program which takes information about the bills put into the urn and computes Mal-Wart's cost of the promotion.

The input contains a number of cases. The first line in each case contains an integer n, 1<=n<=5000, the number of days of the promotion. Each of the subsequent n lines contains a sequence of non-negative integers separated by whitespace. The numbers in the (i+1)-st line of a case give the data for the i-th day. The first number in each of these lines, k, 0≤k≤10⁵, is the number of bills and the subsequent k numbers are positive integers of the bill amounts. No bill is bigger than 10⁶. The total number of all bills is no bigger than 10⁶. The case when n = 0 terminates the input and should not be processed.

For each case of input print one number: the total amount paid to the clients by Mal-Wart as the result of the promotion.

Sample input

5

3 1 2 3

2 1 1

4 10 5 5 1

0

1 2

2

2 1 2

2 1 2

0

Output for sample input

19

2



动态数组最大值最小值差值的和。Multiset。

 1 #include<cstdio>

 2 #include<set>

 3 using namespace std;

 4 typedef long long LL;

 5 int main()

 6 {

 7     LL n,x,maxn,mind,d,sum;

 8     multiset<LL> s;

 9     while(scanf("%I64d",&n)&&n!=0)

10     {

11         sum=0;

12         s.clear();

13         for(LL i=0; i<n; i++)

14         {

15             scanf("%I64d",&x);

16             for(LL j=0; j<x; j++)

17             {

18                 scanf("%I64d",&d);

19                 s.insert(d);

20             }

21             multiset<LL>::iterator it;

22             it=s.begin();

23             mind=*it;

24             s.erase(it);

25             it=s.end(),it--;

26             maxn=*it;

27             s.erase(it);

28             sum+=maxn-mind;

29         }

30         printf("%lld\n",sum);

31     }

32     return 0;

33 }