loop { switch }

#include <stdio.h>
int main() {
    int function = 1, n = 10;
    while (n--) {
        switch (function) {
            case 1: {
                printf("%d\n", function);
                function = 2;
                break;
            }
            case 2: {
                printf("%d\n", function);
                function = 1;
                break;
            }
        }
    }
}