Problem:
Score : 100 points

Problem Statement

There are N stones, numbered 1, 2, \ldots, N.
For each i (1 \leq i \leq N), the height of Stone i is h_i.
Here, h_1 < h_2 < \cdots < h_N holds.

There is a frog who is initially on Stone 1.
He will repeat the following action some number of times to reach Stone N:

If the frog is currently on Stone i, jump to one of the following: Stone i + 1, i + 2, \ldots, N. Here, a cost of (h_j - h_i)^2 + C is incurred, where j is the stone to land on.

Find the minimum possible total cost incurred before the frog reaches Stone N.

Constraints

All values in input are integers.

2 \leq N \leq 2 \times 10^5

1 \leq C \leq 10^{12}

1 \leq h_1 < h_2 < \cdots < h_N \leq 10^6

Input

Input is given from Standard Input in the following format:

N C
h_1 h_2 \ldots h_N

Output

Print the minimum possible total cost incurred.

Sample Input 1

5 6
1 2 3 4 5

Sample Output 1

20

If we follow the path 1 → 3 → 5, the total cost incurred would be ((3 - 1)^2 + 6) + ((5 - 3)^2 + 6) = 20.

Sample Input 2

2 1000000000000
500000 1000000

Sample Output 2

1250000000000

The answer may not fit into a 32-bit integer type.

Sample Input 3

8 5
1 3 4 5 10 11 12 13

Sample Output 3

62

If we follow the path 1 → 2 → 4 → 5 → 8, the total cost incurred would be ((3 - 1)^2 + 5) + ((5 - 3)^2 + 5) + ((10 - 5)^2 + 5) + ((13 - 10)^2 + 5) = 62.

Solution in C++ (GCC 9.2.1) (judge verdict: Time Limit Exceeded)

#include <bits/stdc++.h>
#define ll long long
using namespace std;

void solve()
{
    int n;
    ll c;
    cin >> n >> c;
    ll dp[n];
    int a[n];
    for(int i=0;i<n;i++)
     cin >> a[i];  

    dp[0] = 0;
    dp[1] =(ll)abs(a[1]-a[0])*(ll)abs(a[1]-a[0])+c;
    // 1250000000000
    // 1000891896832
    for(int i=2;i<n;i++)
    {
        dp[i] = INT_MAX;
        for(int j = i-1;j>=0;j--)
        {
            ll k = abs(a[i]-a[j]);
            dp[i] = min(dp[i],k*k+dp[j]+c);
        }
    }
    cout << dp[n-1];
    
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    solve();
}