Tyhh

Dd.cpp

#include<bits/stdc++.h>  
using namespace std;   
int maxSum(int arr[], int n) 
{ 
    // Compute sum of all array elements 
    int cum_sum = 0; 
    for (int i=0; i<n; i++) 
        cum_sum += arr[i]; 
    // Compute sum of i*arr[i] for initial 
    // configuration. 
    int curr_val = 0; 
    for (int i=0; i<n; i++) 
        curr_val += i*arr[i]; 
    // Initialize result 
    int res = curr_val; 
    // Compute values for other iterations 
    for (int i=1; i<n; i++) 
    { 
        // Compute next value using previous  
        // value in O(1) time 
        int next_val = curr_val - (cum_sum - arr[i-1]) 
                       + arr[i-1] * (n-1); 
        // Update current value 
        curr_val = next_val;
        // Update result if required 
        res = max(res, next_val); 
    }  
    return res; 
}   
// Driver code 
int main() 
{ 
    int n;
    cin>>n;
    int arr[n];
    for(int u=0;u<n;u++)
      cin>>arr[u];
    cout << maxSum(arr, n) << endl; 
    return 0; 
}