#include <stdio.h>
int main() {
char string[] = "C is a general-purpose programming language";
int char_set[256] = {0}; // ASCII
for (int i = 0; string[i] != '\0'; i++) {
char_set[(unsigned char)string[i]] = 1; // Mark character as seen
}
for (int i = 0; i < 256; i++) {
if (char_set[i]) {
printf("%c ", i);
}
}
return 0;
}
/*
run:
- C a e g i l m n o p r s u
*/