Check if the String Numeric or Alphabetic

Code

#include <stdio.h>
#include <stdint.h>
#include<string.h>
void classify_string(const char *str) {
    int n=strlen(str);
    int a=0,num=0;
    if(!strcmp(str,""))
    printf("MIXED");
    for(int i=0;i<n;i++){
     if(str[i]>='0'&&str[i]<='9')
     a++;
    }
    if(a==n){
        printf("NUMERIC");
        return;
    }
    for(int i=0;i<n;i++){
     if(str[i]>='A'&&str[i]<='Z' ||str[i]>='a'&&str[i]<='z' )
     num++;
    }
    if(num==n){
        printf("ALPHABETIC");
        return;
    }
    printf("MIXED");
    return;

}

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