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;}