Read N Characters Given Read4 Python Solution

lcpy gen -n 157   # by problem number
lcpy gen -s read_n_characters_given_read4   # by problem name

    Parameter:  char[] buf4
    Returns:    int

buf4[] is a destination, not a source. The results from read4 will be copied to buf4[].

File file("abcde"); // File is "abcde", initially file pointer (fp) points to 'a'
char[] buf4 = new char[4]; // Create buffer with enough space to store characters
read4(buf4); // read4 returns 4. Now buf4 = "abcd", fp points to 'e'
read4(buf4); // read4 returns 1. Now buf4 = "e", fp points to end of file
read4(buf4); // read4 returns 0. Now buf4 = "", fp points to end of file

    Parameters: char[] buf, int n
    Returns:    int

buf[] is a destination, not a source. You will need to write the results to buf[].

Input: file = "abc", n = 4
Output: 3
Explanation: After calling your read method, buf should contain "abc". We read a total of 3 characters from the file, so return 3.
Note that "abc" is the file's content, not buf. buf is the destination buffer that you will have to write the results to.

Input: file = "abcde", n = 5
Output: 5
Explanation: After calling your read method, buf should contain "abcde". We read a total of 5 characters from the file, so return 5.

Input: file = "abcdABCD1234", n = 12
Output: 12
Explanation: After calling your read method, buf should contain "abcdABCD1234". We read a total of 12 characters from the file, so return 12.

class File:
    # Test-harness API: backs the read4 interface with the file content
    def __init__(self, content: str) -> None:
        self.content = content
        self.pos = 0

    def read4(self, buf4: list[str]) -> int:
        # Reads up to 4 consecutive characters into buf4 and returns the
        # number of characters actually read
        chunk = self.content[self.pos : self.pos + 4]
        self.pos += len(chunk)
        for i, char in enumerate(chunk):
            buf4[i] = char
        return len(chunk)


class Solution:
    # Time: O(n)
    # Space: O(1)
    def read(self, buf: list[str], n: int, file: File) -> int:
        i = 0
        buf4 = [""] * 4
        while i < n:
            count = file.read4(buf4)
            if count == 0:
                break
            for j in range(min(count, n - i)):
                buf[i] = buf4[j]
                i += 1
        return i