Best Coder Lotus and Characters

 1 #include<iostream>
 2 #include<cstring>
 3 #include<cstdio>
 4 #include<algorithm>
 5 using namespace std;
 6 struct node{
 7     int v,w;
 8     bool operator < (const node &a) const{
 9         return v<a.v;
10     }
11 }e[29];
12 int T,n;
13 int main()
14 {
15     cin>>T;
16     while(T--){
17         memset(e,0,sizeof(e));
18         scanf("%d",&n);
19         for(int i=1;i<=n;i++)
20           scanf("%d%d",&e[i].v,&e[i].w);
21         sort(e+1,e+n+1);
22         long long ans=0;
23         int k=1,p=1;
24         while(e[k].v<=0) k++;
25         for(int i=k;i<=n;i++)
26           for(int j=1;j<=e[i].w;j++){
27               ans+=e[i].v*p;p++;
28           }
29         printf("%lld\n",ans);
30     }
31     return 0;
32 }