九度 題目1439：Least Common Multiple
原題OJ鏈接：http://ac.jobdu.com/problem.php?pid=1439
題目描述：
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.
輸入：
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.
輸出：
For each problem instance, output a single line containing the corresponding LCM. All results will lie in the range of a 32-bit integer.
樣例輸入：
2
3 5 7 15
6 4 10296 936 1287 792 1
樣例輸出：
105
10296
源代碼：
#include<iostream>
using namespace std;
long long gcd(long long a,long long b){
if(b==0) return a;
else return gcd(b,a%b);
}
int main(){
int ins;
cin>>ins;
for(int i=0;i<ins;i++){
int m;
long long a,b,c;
cin>>m>>a;
for(int j=0;j<m-1;j++){
cin>>b;
a=a*b/gcd(a,b);
}
cout<<a<<endl;
}
return 0;
}