ZOJ 3872 Beauty of Array

#include<cstdio>
#include<cstring>
#include<cmath>
#include<string>
#include<vector>
#include<queue>
#include<algorithm>
#include<iostream>
using namespace std;

const int maxn=100000+10;
int T,n;
int a[maxn];
int pre[10*maxn];
long long f[maxn];

void init()
{
    memset(f,0,sizeof f);
    memset(pre,0,sizeof pre);
}

void read()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++) scanf("%d",&a[i]);
}

void work()
{
    long long ans=0;
    for(int i=1;i<=n;i++)
    {
        long long A=(long long)(i-pre[a[i]]);
        long long B=(long long)a[i];
        f[i]=f[i-1]+A*B;
        pre[a[i]]=i;
        ans=ans+f[i];
    }
    printf("%lld\n",ans);
}

int main()
{
    scanf("%d",&T);
    while(T--)
    {
        read();
        init();
        work();
    }
    return 0;
}