Check if the String Numeric or Alphabetic

Code

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

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