Beauty Values

Beauty Values

Meaning of the title: the number to $ n $,

(Section length * number of different numbers in the interval) defined Beauty Values ​​for all its successive summing subinterval

求Beauty Values

A [i] i represents a number array appears last when, increasing a number i, A [i] due to just before the change in length of the section, there is no increase in the digital type,

DP [i] records ans i between i-1 and the difference

#include<bits/stdc++.h>
using namespace std;
int A[100004];
//int B[100004];
typedef long long ll;
ll dp[100004];
ll ans=0,t=0;
int n;
int main()
{
    scanf("%d",&n);
    int x;
    for(int i=1;i<=n;i++){
        scanf("%d",&x);
        if(A[x]==0){
            ans+=(dp[i-1]+i);
            dp[i]=ans-t;
            A[x]=i;
            t=ans;
        }else{
            ans+=dp[i-1]+i-A[x];
            dp[i]=ans-t;
            A[x]=i;
            t=ans;
        }
    }
    cout<<ans<<'\n';
}