UVa 11547 - Automatic Answer ( a one liner O(1) solution exists)

Link:https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=27&page=show_problem&problem=2542
Lời giải:

#include <cstdio>
	#include <cmath>
	using namespace std;
	int main() {
	int tc;
	long long n;
	scanf("%d", &tc);
	while (tc--) {
	scanf("%lld", &n);
	n = abs((((n * 63 + 7492) * 5 - 498)/10)%10);
	printf("%lld\n", n);
	}
	return 0;
	}