Check if the String Numeric or Alphabetic

Code

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

void classify_string(const char *str) {
    int numeric = 0; 
    int alpha = 0; 
    int len = 0; 
    while (*str != '\0'){ 
        if (*str >= '0' && *str <= '9'){ 
            numeric++;
        } else if ((*str >= 'a' && *str <= 'z') || *str >= 'A' && *str <= 'Z'){ 
            alpha++; 
        }
        str++;
        len++; 
    }
    if (numeric == len){ 
        printf("NUMERIC"); 
    } else if (alpha == len){ 
        printf("ALPHABETIC"); 
    } 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