题目1439：Least Common Multiple

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 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.

For each problem instance, output a single line containing the corresponding LCM. All results will lie in the range of a 32-bit integer.

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

105
10296

#include<iostream>
#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<stack>
using namespace std;
int gcd (int a,int b)
{
if(b==0)
return a;
else
return gcd(b,a%b);
}
int lcm(int a,int b)
{
return (a/gcd(a,b))*b;//使用了一个技巧，先除后乘，避免溢出
}
int main()
{
int n;
long long aim;
while(scanf("%d",&n)!=EOF)
{
long long a[100];
while(n--)
{
int len;
cin>>len;
for(int i=0; i<len; i++)
{
cin>>a[i];
}
aim=a[0];
for(int i=0; i<len; i++)
{
aim=lcm(aim,a[i]);
}
printf("%lldn",aim);
}
}
return 0;
}