BestCoder8 1001.Summary(hdu 4989) 解题报告

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <set>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 typedef __int64 LL;
 9 const int maxn = 100 + 5;
10 LL a[maxn];
11 set<LL> s;
12 set<LL>::iterator ps;
13 
14 int main()
15 {
16     int n;
17     while (scanf("%d", &n) != EOF)
18     {
19         for (int i = 0; i <= maxn; i++)
20             s.clear();
21         for (int i = 0; i < n; i++)
22             scanf("%I64d", &a[i]);
23         for (int i = 0; i < n; i++)
24         {
25             for (int j = i+1; j < n; j++)
26                 s.insert(a[i] + a[j]);
27         }
28         LL ans = 0;
29         for (ps = s.begin(); ps != s.end(); ps++)
30             ans += *ps;
31         printf("%I64d\n", ans);
32     }
33     return 0;
34 }