Problem7298--AtCoder Educational DP Contest —— Z - Frog 3

7298: AtCoder Educational DP Contest —— Z - Frog 3

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Time Limit : 1.000 sec  Memory Limit : 256 MiB

Description

There are N stones, numbered 1,2,…,N. For each i (1≤i≤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,…,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.

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.

Constraints

All values in input are integers.
$2 \leq N \leq 2 \times 10^5$
$1 \leq C \leq 10^{12}$
$1 \leq h_1 < h_2 < \cdots < h_N \leq 10^6$

Sample 1 Input

5 6
1 2 3 4 5

Sample 1 Output

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 2 Input

2 1000000000000
500000 1000000

Sample 2 Output

1250000000000

Sample 3 Input

8 5
1 3 4 5 10 11 12 13

Sample 3 Output

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

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