Parse Comma-Separated Integers into an Array

#include <stdio.h>
#include <stdint.h>

uint8_t convert_digit(const char *digits, int len) {
    uint8_t result = 0;
    char offset = '0';
    uint8_t multiplier = 1;

    while (len > 0) {
        result += (digits[len - 1] - offset) * multiplier;
        multiplier *= 10;
        len--;
    }
    return result;
}

void parse_csv_to_array(const char *str, uint8_t *arr, uint8_t *count) {
    // init
    *count = 0;
    int index = 0;
    char digits[4] = "";
    int index_digits = 0;

    // parse the string
    while (str[index] != '\0') {
        if (str[index] == ',') {
            // comma found
            digits[index_digits] = '\0';
            arr[*count] = convert_digit(digits, index_digits);
            (*count)++;
            index_digits = 0;
        } else {
            // digit found
            digits[index_digits++] = str[index];
        }
        index++;

        // decode number after last comma
        if (str[index] == '\0') {
            arr[*count] = convert_digit(digits, index_digits);
            (*count)++;
        }
    }
}

int main() {
    char str[101];
    fgets(str, sizeof(str), stdin);

    // Remove newline
    uint8_t i = 0;
    while (str[i]) {
        if (str[i] == '\n') {
            str[i] = '\0';
            break;
        }
        i++;
    }

    uint8_t arr[20];
    uint8_t count = 0;

    parse_csv_to_array(str, arr, &count);

    for (uint8_t i = 0; i < count; i++) {
        printf("%u", arr[i]);
        if(i < count - 1){
            printf(" ");
        }
    }
    return 0;
}