Check if the String Numeric or Alphabetic

Code

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

void classify_string(const char *str) {
    // Your logic here
    int alpha = 0, num = 0, mixed = 0;
    int i = 0;
    while(str[i] != '\0')
    {
        if(str[i]>='A' && str[i]<='Z' || str[i]>='a' && str[i]<='z')
            alpha+=1;
        else if(str[i]>='0' && str[i]<='9')
            num+=1;
        else
            mixed+=1;
        i++;
    }
    if(num==0 && mixed==0)  printf("ALPHABETIC");
    else if(alpha==0 && mixed==0)    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