Question

I’m trying to figure out how to create a complex loop but I don’t find any solutions.

I have 2 tables and each of which can seat arbitrary amount of people.
I would like to create a loop to get all possibilities where I can put the people!
Each person are represented by an ID for example for 5 peoples.
each of digits are the person’s ID.
I need to know what are the possible ways to seat the people!

table1   table2

(nobody) 12345
1        2345
2        1345
3        1245
4        1235
5        1234
12       345
13       245
14       235
15       234
23       145
24       135
25       134
34       125
35       124
45       123

Answer 1

#include <stdio.h>

int main(void) {
    unsigned people = 5;

    printf("There are %u lights.\n", people);

    for (unsigned i = 0; i < 1u << people; i++) {
        for (unsigned p = 0; p < people; p++) {
            if (i >> p & 1u) {
                printf("%u", p + 1);
            }
        }
        fputs("\t|\t", stdout);
        for (unsigned p = 0; p < people; p++) {
            if (!(i >> p & 1u)) {
                printf("%u", p + 1);
            }
        }
        putchar('\n');
    }

    return 0;
}