Count Alphabets Digits and Symbols in a String

Code

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

void classify_chars(const char *str, uint8_t *alpha, uint8_t *digit, uint8_t *symbol) {
    // Your logic here
  uint8_t alphabets = 0;
    uint8_t digits = 0;
    uint8_t symbols = 0;
    int i;

    if (str == 0 || alpha == 0 || digit == 0 || symbol == 0)
        return;

    for (i = 0; str[i] != '\0'; i++)
    {
        if ((str[i] >= 'A' && str[i] <= 'Z') ||
            (str[i] >= 'a' && str[i] <= 'z'))
        {
            alphabets++;
        }
        else if (str[i] >= '0' && str[i] <= '9')
        {
            digits++;
        }
        else if (str[i] != ' ')
        {
            symbols++;
        }
    }

    /* store results via pointers */
    *alpha  = alphabets;
    *digit  = digits;
    *symbol = symbols;
    
}

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 alpha = 0, digit = 0, symbol = 0;
    classify_chars(str, &alpha, &digit, &symbol);
    printf("Alphabets = %u\nDigits = %u\nSymbols = %u", alpha, digit, symbol);
    return 0;
}

Solving Approach