uva 11136 multiset

 1 #include <iostream>
 2 #include <cstring>
 3 #include <cstdio>
 4 #include <set>
 5 using namespace std;
 6 
 7 multiset<int> s;
 8 multiset<int>::iterator it;
 9 
10 int main ()
11 {
12     int n;
13     while ( scanf("%d", &n), n )
14     {
15         long long sum = 0;
16         s.clear();
17         for ( int i = 0; i < n; i++ )
18         {
19             int m;
20             scanf("%d", &m);
21             while ( m-- )
22             {
23                 int tmp;
24                 scanf("%d", &tmp);
25                 s.insert(tmp);
26             }
27             it = s.begin();
28             int lb = (*it);
29             s.erase(it);
30             it = s.end();
31             it--;
32             int ub = (*it);
33             s.erase(it);
34             sum += ub - lb;
35         }
36         printf("%lld\n", sum);
37     }
38     return 0;
39 }