uva 1428

https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=4174

  #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<vector>
 using namespace std;
 #define lowbit(x) ((x)&(-x))
 typedef long long LL;
 const int maxn =  + ;
 int a[maxn],s[maxn];
 LL b[maxn];
 int iNum;

 void add(int x,int v)
 {
     while (x<=iNum)
     {
         s[x]+=v;
         x += lowbit(x);
     }

 }

 int sum (int x)
 {
     int ret = ;
     while (x>)
     {
         ret += s[x];
         x -= lowbit(x);
     }
     return ret;
 }
 int main()
 {

     int T;
     cin >> T;
     while (T--)
     {
         int n;
         cin >> n;
         memset(s, , sizeof(s));
         for (int i = ;i<=n;i++)
         {

             cin >> a[i];

             iNum = max(iNum,a[i]);
         }

         for (int i = ;i<=n;i++)
         {

             b[i] = sum(a[i]-);
             add(a[i],);
         }
         LL ans = ;
         memset(s,,sizeof(s));
         for (int i = n;i>;i--)
         {
             LL d = sum(a[i]-);
             add(a[i],);
             ans += (b[i] * (n - i - d)) + d * (i -  - b[i]);

         }
         cout << ans << endl;
     }
     return ;
 }