pub fn make_string_arr(s: &str) -> Vec<String> {
    s.trim_matches(&['[', ']'][..])
        .split(',')
        .map(|s| s.trim_matches(&['"',' ']).to_string())
        .collect()
}
pub fn make_arr(s: &str) -> Vec<i32> {
    s.trim_matches(&['[', ']'][..])
        .split(',')
        .map(|x| {
            let x = x.trim();
            if x == "null" {
                -1
            } else {
                x.parse::<i32>().unwrap()
            }
        })
        .collect()
}

pub fn make_matrix(s: &str) -> Vec<Vec<i32>> {
    let s = s.trim();

    // Remove only the outermost pair of brackets if present, e.g. "[[1,2],[3,4]]" -> "[1,2],[3,4]"
    let inner = if s.len() >= 2 && s.starts_with('[') && s.ends_with(']') {
        &s[1..s.len() - 1]
    } else {
        s
    }
    .trim();

    if inner.is_empty() {
        return Vec::new();
    }

    let bytes = inner.as_bytes();
    let mut i = 0usize;
    let mut rows: Vec<Vec<i32>> = Vec::new();
    while i < bytes.len() {
        // find next '['
        while i < bytes.len() && bytes[i] != b'[' {
            i += 1;
        }
        if i >= bytes.len() {
            break;
        }
        let start = i + 1; // byte index after '['
        i = start;
        // find matching ']'
        while i < bytes.len() && bytes[i] != b']' {
            i += 1;
        }
        let end = i; // exclusive
        // move i past ']' for next iteration (if in bounds)
        if i < bytes.len() {
            i += 1;
        }

        if end <= start {
            // empty row like []
            rows.push(Vec::new());
            continue;
        }

        let row_str = &inner[start..end];
        let row_vec: Vec<i32> = row_str
            .split(',')
            .map(|x| {
                let x = x.trim();
                if x == "null" || x.is_empty() {
                    -1
                } else {
                    x.parse::<i32>().unwrap()
                }
            })
            .collect();
        rows.push(row_vec);
    }

    rows
}

pub fn make_char_matrix(s: &str) -> Vec<Vec<char>> {
    let s = s.trim();

    // Remove only the outermost pair of brackets if present, e.g. "[[1,2],[3,4]]" -> "[1,2],[3,4]"
    let inner = if s.len() >= 2 && s.starts_with('[') && s.ends_with(']') {
        &s[1..s.len() - 1]
    } else {
        s
    }
        .trim();

    if inner.is_empty() {
        return Vec::new();
    }

    let bytes = inner.as_bytes();
    let mut i = 0usize;
    let mut rows: Vec<Vec<char>> = Vec::new();
    while i < bytes.len() {
        // find next '['
        while i < bytes.len() && bytes[i] != b'[' {
            i += 1;
        }
        if i >= bytes.len() {
            break;
        }
        let start = i + 1; // byte index after '['
        i = start;
        // find matching ']'
        while i < bytes.len() && bytes[i] != b']' {
            i += 1;
        }
        let end = i; // exclusive
        // move i past ']' for next iteration (if in bounds)
        if i < bytes.len() {
            i += 1;
        }

        if end <= start {
            // empty row like []
            rows.push(Vec::new());
            continue;
        }

        let row_str = &inner[start..end];
        let row_vec: Vec<char> = row_str
            .split(',')
            .map(|x| {
                let x = x.trim().trim_matches('"');
                if x == "null" || x.is_empty() {
                    ' '
                } else {
                    x.to_string().chars().nth(0).unwrap()
                }
            })
            .collect();
        rows.push(row_vec);
    }

    rows
}
pub fn make_string_matrix(s: &str) -> Vec<Vec<String>> {
    let s = s.trim();

    // Remove only the outermost pair of brackets if present, e.g. "[[1,2],[3,4]]" -> "[1,2],[3,4]"
    let inner = if s.len() >= 2 && s.starts_with('[') && s.ends_with(']') {
        &s[1..s.len() - 1]
    } else {
        s
    }
        .trim();

    if inner.is_empty() {
        return Vec::new();
    }

    let bytes = inner.as_bytes();
    let mut i = 0usize;
    let mut rows: Vec<Vec<String>> = Vec::new();
    while i < bytes.len() {
        // find next '['
        while i < bytes.len() && bytes[i] != b'[' {
            i += 1;
        }
        if i >= bytes.len() {
            break;
        }
        let start = i + 1; // byte index after '['
        i = start;
        // find matching ']'
        while i < bytes.len() && bytes[i] != b']' {
            i += 1;
        }
        let end = i; // exclusive
        // move i past ']' for next iteration (if in bounds)
        if i < bytes.len() {
            i += 1;
        }

        if end <= start {
            // empty row like []
            rows.push(Vec::new());
            continue;
        }

        let row_str = &inner[start..end];
        let row_vec: Vec<String> = row_str
            .split(',')
            .map(|x| {
                let x = x.trim().trim_matches('"');
                if x == "null" || x.is_empty() {
                    "".to_string()
                } else {
                    x.to_string()
                }
            })
            .collect();
        rows.push(row_vec);
    }

    rows
}