Ex3 Bun

#include <stdio.h>
#include <stdlib.h>

unsigned ZigZag(unsigned n, unsigned i, unsigned j, unsigned pivot, unsigned lung) {
    if (lung) {
        n = n - ((2 * (i > lung) + (j > lung) ) * pivot);
        if (i > lung ) i -= lung;
        if (j > lung ) j -= lung;

        return ZigZag(n, i, j, pivot/ 4, lung /2);
    }
    return n;
}

int main() {
    unsigned n, i, j , q;
    FILE *f, *g;
    f = fopen("in.txt", "r");
    g = fopen("out.txt", "w");
    fscanf(f, "%u%u", &n, &q);

    while (q) {
        fscanf(f, "%u%u", &i, &j);
        fprintf(g, "%u\n", ZigZag(1 << 2 * n, i, j ,  1 << 2 *(n-1), 1 <<( n - 1)));
        q--;
    }
    fclose(f);
    fclose(g);
    return 0;
}