Count Alphabets Digits and Symbols in a String

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

void classify_chars(const char *str, uint8_t *alpha, uint8_t *digit, uint8_t *symbol) {
    int idx = 0;

    while(str[idx] != '\0') {
        if ((str[idx] >= 'a') && (str[idx] <= 'z') || ((str[idx] >= 'A') && (str[idx] <= 'Z'))) {
            (*alpha)++;
        }else if ((str[idx] >= '0') && (str[idx] <= '9')) {
            (*digit)++;
        }else if (str[idx] != ' '){
            (*symbol)++;
        }
        idx++;
    }
}

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;
}