[hackerrank]John and GCD list

https://www.hackerrank.com/contests/w8/challenges/john-and-gcd-list

简单题，GCD和LCM。

#include <vector>

#include <iostream>



using namespace std;



int gcd(int a, int b) {

	if (a % b == 0) {

		return b;

	} else {

		return gcd(b, a % b);

	}

}



int lcm(int a, int b) {

	return a * b / gcd(a, b);

}



int main() {

	int T;

	cin >> T;

	while (T--) {

		int N;

		cin >> N;

		vector<int> A(N);

		for (int i = 0; i < N; i++) {

			cin >> A[i];

		}

		vector<int> B(N + 1);

		for (int i = 1; i < N; i++) {

			B[i] = lcm(A[i], A[i - 1]);

		}

		B[0] = A[0];

		B[N] = A[N - 1];

		for (int i = 0; i <= N; i++) {

			cout << B[i] << " ";

		}

		cout << endl;

	}

	

	

    return 0;

}