Check if the String Numeric or Alphabetic

Code

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

void classify_string(const char *str) {
   int digit = 0, alpha = 0, other = 0;

    if (*str == '\0') {
        printf("MIXED\n");
        return;
    }

    while (*str)
    {
        if (*str >= '0' && *str <= '9') 
        {
            digit = 1;
        } 
        else if ((*str >= 'A' && *str <= 'Z') || (*str >= 'a' && *str <= 'z')) {
            alpha = 1;
        } 
        else 
        {
            other = 1;
        }
        str++;
    }

    if (digit && !alpha && !other) 
    {
        printf("NUMERIC\n");
    } 
    else if (!digit && alpha && !other) 
    {
        printf("ALPHABETIC\n");
    } 
    else 
    {
        printf("MIXED\n");
    }
}

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++;
    }

    classify_string(str);
    return 0;
}

Solving Approach