Check if the String Numeric or Alphabetic

Code

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

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