Check if the String Numeric or Alphabetic

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

void classify_string(const char *str) {
    int num_found, alph_found = 0;
    for (int i = 0; str[i] != '\0'; i++) {
        int not_spec_char = 0;
        if (str[i] >= '0' && str[i] <= '9') {
            num_found++;
            not_spec_char = 1;
        }

        if ((str[i] >= 'a' && str[i] <= 'z') || (str[i] >= 'A' && str[i] <= 'Z')) {
            alph_found++;
            not_spec_char = 1;
        }

        if ((num_found != 0 && alph_found != 0) || !not_spec_char) {
            printf("MIXED\n");
            return;
        }
    }
    if (num_found) printf("NUMERIC\n");
    if (alph_found) printf("ALPHABETIC\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;
}