Problem Description
The least common multiple (LCM) of a set of positive integers is the smallest positive integer which is divisible by all the numbers in the set. For example, the LCM of 5, 7 and 15 is 105.
(一组正整数的最小公倍数(LCM)是最小正整数,其可被集合中的所有数字整除。例如,5,7和15的LCM是105。)
Input
Input will consist of multiple problem instances. The first line of the input will contain a single integer indicating the number of problem instances. Each instance will consist of a single line of the form m n1 n2 n3 ... nm where m is the number of integers in the set and n1 ... nm are the integers. All integers will be positive and lie within the range of a 32-bit integer.
(输入将包含多个问题实例。输入的第一行将包含一个整数,表示问题实例的数量。每个实例将由m n1 n2 n3 ... nm形式的单个行组成,其中m是集合中的整数数,n1 ... nm是整数。所有整数都是正数,并且位于32位整数的范围内。)
Output
For each problem instance, output a single line containing the corresponding LCM. All results will lie in the range of a 32-bit integer.
(对于每个问题实例,输出包含相应LCM的单行。所有结果都将位于32位整数的范围内。)
Sample Input
2
3 5 7 15
6 4 10296 936 1287 792 1
Sample Output
105
10296
用gcd逐个求出相邻两数字的最小公倍数lcm
LCM(a,b) = a * b / GCD(a,b)
注意:求解最小公倍数时,先乘后除,乘法明显可能溢出(wa了一发),所以应该先除后乘
LCM(a,b) = a / GCD(a,b)* b
#include using namespace std; typedef long long ll; ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a%b); } int main() { ll r; cin >> r; while (r--) { ll n, m1, m2, s; cin >> n>> m1; s = m1; for (int i = 0; i < n-1; i++) { cin >> m1; s = m1/gcd(m1, s)*s; } cout << s<<endl; } }