Remove Duplicate Characters from a String

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

void remove_duplicates(char *str) {

	//Your logic here
    int i=0,k,mark;
    uint8_t str2[256]={0};
    while(str[i]!='\0'){
      
       if ((str2[(unsigned char)str[i]]==1)) {
         k=i;
        while(str[k]!='\0'){
            str[k]=str[k+1];
            k++;
        }
        
       }
       else {
            str2[(unsigned char)str[i]] = 1;
            i++;
        }
    }
}
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;
}