Check if the String Numeric or Alphabetic

Code

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

void classify_string(const char *str) {
        int alpha=0,numeric=0;
        if(*str == '\0'){
            printf("MIXED");
            return;
        }
        while(*str != '\0'){
            if(( *str >= 'A' && *str <= 'Z') || (*str >= 'a' && *str <= 'z')){
                alpha = 1;
            }
            else if(*str >= '0' && *str <= '9'){
                numeric = 1;
            }
            else{
                printf("MIXED");
                return;
            }
            str++;
        }
        if(alpha && !numeric){
            printf("ALPHABETIC");
            return;
        }
        else if(!alpha && numeric){
            printf("NUMERIC");
            return;
        }
        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