A13947 | Buy the String

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.

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 $n$ .

For each test case print a single integer — the minimum number of coins needed to buy the string.