P29991 [洛谷] [JOISC2022] Copy and Paste 3
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题目描述

Problem Background

JOISC2022 D2T1

Problem Description

JOI Corporation is a company renowned for its "useless inventions." Recently, JOI Corporation developed a new editor called "Useless Editor."

In this editor, you can perform the following operations to input a string. Let $X$ be the string on the screen and $Y$ be the string in the clipboard, both initially empty:

  • Operation A: Input character $c$, updating $X$ to $X + c$.
  • Operation B: Select all characters and cut them, updating $Y$ to $X$ and setting $X$ to an empty string.
  • Operation C: Paste the clipboard's string to the end of the current string, updating $X$ to $X + Y$.

For strings or characters $x$ and $y$, $x + y$ denotes the concatenation of $x$ and $y$. Each operation A, B, and C costs $A$, $B$, and $C$ units of time, respectively.

You have installed the "Useless Editor" and want to input a string $S$ of length $N$ as quickly as possible.

You need to calculate the minimum time required to input the string $S$.

Input Format

The first line contains an integer $N$, the length of the string.

The second line contains a string $S$ of length $N$, the string to be input.

The third line contains an integer $A$, the cost of operation A.

The fourth line contains an integer $B$, the cost of operation B.

The fifth line contains an integer $C$, the cost of operation C.

Output Format

Output a single integer, the minimum time required to input the string $S$.

Sample Input and Output

Sample Input #1

11
mississippi
10
5
2

Sample Output #1

88

Sample Input #2

16
aaaaaaaaaaaaaaaa
1
1
1

Sample Output #2

9

Sample Input #3

18
aababbbababbbaabbb
1000000000
100000
10000000

Sample Output #3

8060200000

Notes/Hints

Sample Explanation #1

The following is an optimal sequence of operations:

Round Operation Explanation $X$ $Y$ Cost Total Time
- - - "" "" - $0$
$1$ Operation A Input character "s" "" $10$ $10$
$2$ Operation B Select and cut "" "s" $5$ $15$
$3$ Operation C Paste at end "s" "s" $2$ $17$
$4$ Operation C Paste at end "ss" "s" $2$ $19$
$5$ Operation A Input character "ssi" "s" $10$ $29$
$6$ Operation B Select and cut "" "ssi" $5$ $34$
$7$ Operation A Input character "m" "ssi" $10$ $44$
$8$ Operation A Input character "mi" "ssi" $10$ $54$
$9$ Operation C Paste at end "missi" "ssi" $2$ $56$
$10$ Operation C Paste at end "mississi" "ssi" $2$ $58$
$11$ Operation A Input character "mississip" "ssi" $10$ $68$
$12$ Operation A Input character "mississipp" "ssi" $10$ $78$
$13$ Operation A Input character "mississippi" "ssi" $10$ $88$

This sample satisfies the constraints of subtasks $3, 4, 5, 6$.

Sample Explanation #2

An optimal strategy is as follows:

Round Operation Explanation $X$ $Y$ Cost Total Time
- - - "" "" - $0$
$1$ Operation A Input character "a" "" $1$ $1$
$2$ Operation A Input character "aa" "" $1$ $2$
$3$ Operation A Input character "aaa" "" $1$ $3$
$4$ Operation A Input character "aaaa" "" $1$ $4$
$5$ Operation B Select and cut "" "aaaa" $1$ $5$
$6$ Operation C Paste at end "aaaa" "aaaa" $1$ $6$
$7$ Operation C Paste at end "aaaaaaaa" "aaaa" $1$ $7$
$8$ Operation C Paste at end "aaaaaaaaaaaa" "aaaa" $1$ $8$
$9$ Operation C Paste at end "aaaaaaaaaaaaaaaa" "aaaa" $1$ $9$

This sample satisfies the constraints of subtasks $2, 3, 4, 5, 6$.

Sample Explanation #3

This sample satisfies the constraints of subtasks $3, 4, 5, 6$.

Data Range

For all data, the following constraints apply:

  • $1 \leq N \leq 2500$
  • $S$ is a string of length $N$ consisting of lowercase letters.
  • $1 \leq A, B, C \leq 10^9$

Detailed subtask constraints and scores are as follows:

Subtask Number Additional Constraints Score
$1$ $N = 3$ $1$
$2$ $S$ consists only of the character a $5$
$3$ $N \leq 30$ $14$
$4$ $N \leq 200$ $10$
$5$ $N \leq 1000$ $32$
$6$ No additional constraints $38$
输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
11 mississippi 10 5 2
样例输出
88