#include <cstdio>

/**
 * 779. K-th Symbol in Grammar
 * We build a table of n rows (1-indexed). We start by writing 0 in the 1st row. Now in every subsequent row, we look at the previous row and replace each occurrence of 0 with 01, and each occurrence of 1 with 10.
 * - For example, for n = 3, the 1st row is 0, the 2nd row is 01, and the 3rd row is 0110.
 * Given two integer n and k, return the kth (1-indexed) symbol in the nth row of a table of n rows.
 */

class Solution {
public:
    static int kthGrammar(int n, int k) {
        --k;
        int cur = 0;
        while (--n)
            cur ^= !!(k & (1 << (n - 1)));
        return cur;
    }
};

int main() {
    std::printf("%d\n", Solution::kthGrammar(1, 1));
    std::printf("%d\n", Solution::kthGrammar(2, 1));
    std::printf("%d\n", Solution::kthGrammar(2, 2));
    std::printf("%d\n", Solution::kthGrammar(3, 1));
    std::printf("%d\n", Solution::kthGrammar(3, 2));
    std::printf("%d\n", Solution::kthGrammar(3, 3));
    std::printf("%d\n", Solution::kthGrammar(3, 4));
    return 0;
}