Check if the String Numeric or Alphabetic

Code

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

void classify_string(const char *str) {
    int fn=0,fa=0,fm=0,i=0;
    while(str[i] != '\0'){
        if(str[i] >= '0' && str[i] <='9'){
            fn++;
        }
        else if((str[i] >= 'A' && str[i] <='Z') || (str[i] >= 'a' && str[i] <='z')){
            fa++;
        }
        else{
            fm++;
        }
        i++;
    }
    if(fn && fa || fm){
        printf("MIXED");
    }
    else if(fa){
        printf("ALPHABETIC");
    }
    else if(fn){
        printf("NUMERIC");
    }
}

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