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 check;
    if(str[i] >= '0' && str[i] <= '9'){
        check = 1;
        while(str[i]){
            if(str[i] < '0' || str[i] > '9'){
                check = 0;
                break;
            }
            i++;
        }
        if(check == 1) printf("NUMERIC");
        else printf("MIXED");
    }
    else if ((str[i] >= 'a' && str[i] <= 'z') || (str[i] >= 'A' && str[i] <= 'Z')){
        check = 1;
        while(str[i]){
            if(!((str[i] >= 'a' && str[i] <= 'z') || (str[i] >= 'A' && str[i] <= 'Z'))){
                check = 0;
                break;
            }
            i++;
        }
        if(check == 1) printf("ALPHABETIC");
        else printf("MIXED");
    }
    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