1 #include<cstdio> 2 #include<cstring> 3 #include<cctype> 4 typedef long long ll; 5 const int maxn=5e4+10; 6 int T,n,a[maxn],c[maxn],l[maxn],r; 7 ll ans; 8 inline void modify(int x){while (x<=n) c[x]++,x+=x&-x;} 9 inline int sum(int x)10 {11     int ret=0;12     while (x>0) ret+=c[x],x-=x&-x;13     return ret;14 }15 inline void read(int &x)16 {17     char ch;x=0;18     while (!isdigit(ch=getchar()));19     do x=x*10+ch-‘0‘;20     while (isdigit(ch=getchar()));21 }22 int main()23 {24     read(T);25     while (T--)26     {27         read(n);28         for (int i=1;i<=n;i++) read(a[i]);29         memset(c,0,sizeof(int)*(n+1));30         for (int i=1;i<=n;i++)31         {32             l[i]=sum(a[i]);33             modify(a[i]);34         }35         memset(c,0,sizeof(int)*(n+1));ans=r=0;36         for (int i=n;i>=1;i--)37         {38             ans+=(ll)l[i]*r;39             r+=sum(n-a[i]+1);40             modify(n-a[i]+1);41         }42         printf("%I64d\n",ans);43     }44     return 0;45 }