Remove Duplicate Characters from a String

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

void remove_duplicates(char *str) {
	  int check[200] = {0};  // keep track of characters check
    int i, j = 0;
    for (i = 0; str[i] != '\0'; i++) {
        unsigned char c = str[i];
        if (!check[c]) {
            str[j++] = c;  
            check[c] = 1;    // mark as check
        }
    }
    str[j] = '\0'; // terminate final string

    }

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;
}