费马大定理结合勾股数-HDU6441

费马大定理：a^n + b^n = c^n在n > 2无解

只考虑n为1和2的情况

n为1，则b=1,c=a+1

n为2，构造勾股数：a是奇数时，tmp = a / 2;　　b = (tmp + 1) * tmp * 2;　　c = b + 1;　　举例：5、12、13.

a是偶数时，tmp = a / 2 - 1;　　b = (tmp + 2) * tmp;　　c = b + 2;　　举例：8、15、17.

#include <cstdio>
typedef long long ll;
int main() {
	int T;
	scanf("%d", &T);
	
	while (T--) {
		ll n, a, b, c;
		scanf("%lld%lld", &n, &a);
		if (n == 1) {
			printf("%lld %lld\n", 1, 1+a);
		}
		else if (n == 2) {
			if (a % 2 == 1) {
				ll tmp = (a-1)/2;
				b = 2*tmp*tmp+2*tmp;
				c = b+1;
				printf("%lld %lld\n", b, c);
			}
			else {
				ll tmp = a/2 - 1;
				b = tmp*tmp + 2*tmp;
				c = b + 2;
				printf("%lld %lld\n", b, c);
			}
		}
		else printf("-1 -1 \n");
	}
	return 0;
}