Count Alphabets Digits and Symbols in a String

#include <stdio.h>
#include <stdint.h>
void classify_chars(const char *str, uint8_t *alpha, uint8_t *digit, uint8_t *symbol) {
for(int i=0;str[i]!='\0';i++){
    char t=str[i];
    bool al,di;
    al=0;di=0;
    if((t>=48)&&(t<=57)){
        (*digit)++;
        di=1;
    }
    else if(((t>=65)&&(t<=90))||((t>=97)&&(t<=122))){
        (*alpha)++;al=1;
    }
    else if((t!=' ')&&(~di)&&(~al)){
    (*symbol)++;
    }

  
}
}

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++;
    }

    uint8_t alpha = 0, digit = 0, symbol = 0;
    classify_chars(str, &alpha, &digit, &symbol);
    printf("Alphabets = %u\nDigits = %u\nSymbols = %u", alpha, digit, symbol);
    return 0;
}