Check if the String Numeric or Alphabetic

Code

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

void classify_string(const char *str) {
    // Your logic here

    int len = 0;
    int alpha = 0;
    int num = 0;
    while (str[len] != '\0'){
        if ((str[len] >= 'a' && str[len] <= 'z') || (str[len] >= 'A' && str[len] <= 'Z')) ++alpha;
        else if ((str[len] >= '0' && str[len] <= '9')) ++num;
        ++len;
    }

    if (alpha == len) printf("ALPHABETIC");
    else if (num == len) printf("NUMERIC");
    else printf("MIXED");
}

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