Remove Duplicate Characters from a String

Code

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

void remove_duplicates(char *str) {
    uint8_t dict[0x7f] = {0};
    char *p0 = str;
    char *p1 = p0;
    while (*p0) {
        if (!dict[*p0]++)
            *p1++ = *p0;
        p0++;
    }
    *p1 = '\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