【辗转相除法】HDU1019Least Common Multiple

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1019

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

23 5 7 156 4 10296 936 1287 792 1

 

Sample Output

10510296

代码：

#include<iostream>#include<string>#include<algorithm>#define LL long longusing namespace std;LL gcd(LL a,LL b){    return b?gcd(b,a%b):a;}int main(){    int t,m;    cin.sync_with_stdio(false);    cin>>t;    while(t--){        cin>>m;        LL sum=1,a;        for(int i=0;i<m;i++){            cin>>a;            sum=sum/gcd(sum,a)*a;        }        cout<<sum<<endl;    }    return 0;}