Check if the String Numeric or Alphabetic

Code

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

void classify_string(const char *str) {
    // Your logic here
    uint8_t flag = 0x11; // 01-NUMERIC, 10-ALPHABETIC, 00-MIXED
    while (*str) {
        if (*str >= '0' && *str <= '9') {
            flag &= 0x01;
        } else if ((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z')) {
            flag &= 0x10;
        } 
        else {
            flag = 0x11;
        }
        str++;
    }

    if (flag == 0x01) {
        printf("NUMERIC");
    } else if (flag == 0x10) {
        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