1019 Least Common Multiple

Least Common Multiple

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.

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.

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.

Sample Input
2
3 5 7 15
6 4 10296 936 1287 792 1

Sample Output
105
10296

#include<bits/stdc++.h>
using namespace std;
using LL=int64_t;
const int INF=0x3f3f3f3f;
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    LL T;
    while(cin>>T) {
        for(int k=0;k<T;k++) {
            int n;
            cin>>n;
            LL sum=0,ans,x;
            for(int i=0;i<n;i++) {
                    cin>>x;
                if(i==0) ans=sum=x;
                else {
                    LL temp=ans*x/__gcd(ans,x);
                    ans=temp;
                    sum=max(sum,ans);
                }
            }
            cout<<sum<<endl;
        }
    }
    return 0;
}