Remove Duplicate Characters from a String

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

void remove_duplicates(char *str) {
	//Your logic here
    uint8_t hash[256]={0};

    uint8_t read_index=0, write_index=0, ch;

    while(str[read_index] != '\0'){
        ch = (uint8_t)str[read_index];
        if(!hash[ch]){
            hash[ch] = 1;
            str[write_index++] = str[read_index];
        }
        read_index++;
    }
    str[write_index] = '\0';    //string will be unique till the write index, so terminate it after that
    }

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++;
    }

    remove_duplicates(str);
    printf("%s", str);
    return 0;
}