Remove Duplicate Characters from a String

Code

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


void remove_duplicates(char *str) {

    uint8_t isDuplicated = 0;

    char buffer[256];
    memset(buffer,'\0',sizeof(buffer));
    char c = ' ';
    int n = 0;

    for(int i=0;i<strlen(str);i++)
    {
        c = str[i];
        // search
        for(int j=0;j<n;j++)
        {
            if(c==buffer[j])
            {
                isDuplicated = 1;
                break;
            }

            else
            {
                isDuplicated = 0;
            }
        }

        if (!isDuplicated)
        {
            buffer[n] = str[i];
            n++;
        }
    }

    buffer[n] = '\0';

    for (int i=0;i<strlen(buffer);i++) {
        str[i] = buffer[i];
    }

    str[n] = '\0';

}

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;
}

Solving Approach