Remove Duplicate Characters from a String

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

void remove_duplicates(char *str) {
	//Your logic here
    //determine the length
    int len =0;
    while(!(*str=='\0')) {
        len++;
        str++;
    }
    //come back to the origin
    str-=(len);
    for (int i = 0; i< (len);i++){ //focus on char i 
        for (int j = i+1; j < len; j++){
            if (*(str+j) == *(str+i)){
                for(int k = j; k < (len+1);k++){ //rebuild
                    *(str+k)=*(str+k+1);
                }
                len--; //shorten the length
                j=i; //restart "j" loop
            }
        }
    }
    }

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;
}