Check if the String Numeric or Alphabetic

Code

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

void classify_string(const char *str) {
    int seen_digit = 0; 
    int seen_alpha = 0; 
    int seen_mixed = 0; 
    int i = 0; 

    while (str[i] != '\0')
    {
        if ((str[i] >= 'a' && str[i] <= 'z') || (str[i] >= 'A' && str[i] <= 'Z'))
        {
            seen_alpha = 1; 
        }
        else if ((str[i] >= '0' && str[i] <= '9'))
        {
            seen_digit = 1; 
        }
        else
        {
            seen_mixed = 1; 
            break; 
        }

        i++;
    }

    if (seen_mixed || (seen_alpha && seen_digit))
    {
        printf("%s", "MIXED");
    }
    else if (seen_alpha && !seen_digit)
    {
        printf("%s", "ALPHABETIC"); 
    }
    else if (!seen_alpha && seen_digit)
    {
        printf("%s", "NUMERIC");
    }
}

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