题目描述
You are given four integers $n$, $c_0$, $c_1$ and $h$ and a binary string $s$ of length $n$.
A binary string is a string consisting of characters $0$ and $1$.
You can change any character of the string $s$ (the string should be still binary after the change). You should pay $h$ coins for each change.
After some changes (possibly zero) you want to buy the string. To buy the string you should buy all its characters. To buy the character $0$ you should pay $c_0$ coins, to buy the character $1$ you should pay $c_1$ coins.
Find the minimum number of coins needed to buy the string.
Input
The first line contains a single integer $t$ ($1 \leq t \leq 10$) — the number of test cases. Next $2t$ lines contain descriptions of test cases.
The first line of the description of each test case contains four integers $n$, $c_{0}$, $c_{1}$, $h$ ($1 \leq n, c_{0}, c_{1}, h \leq 1000$).
The second line of the description of each test case contains the binary string $s$ of length $n$.
Output
For each test case print a single integer — the minimum number of coins needed to buy the string.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
In the first test case, you can buy all characters and pay $3$ coins, because both characters $0$ and $1$ costs $1$ coin.
In the second test case, you can firstly change $2$-nd and $4$-th symbols of the string from $1$ to $0$ and pay $2$ coins for that. Your string will be $00000$. After that, you can buy the string and pay $5 \cdot 10 = 50$ coins for that. The total number of coins paid will be $2 + 50 = 52$.