1019 Least Common Multiple

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 51959    Accepted Submission(s): 19706

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

思路：求多个数的最小公倍数

 1 #include<iostream>
 2 using namespace std;
 3 long long  gcd(long long  c,long long  b)
 4 {
 5     return b? gcd(b,c%b):c;
 6 }
 7 int main()
 8 {
 9     int t;
10     cin>>t;
11     while(t--)
12     {
13         int n;
14         long long a[10000];
15         cin>>n;
16         for(int i=0;i<n;i++)
17         {
18             cin>>a[i];
19         }
20         for(int i=1;i<n;i++)
21         {
22             a[i]=a[i]*a[i-1]/gcd(a[i],a[i-1]);
23         }
24         cout<<a[n-1]<<endl;
25     }
26     return 0;
27  } 

求最大公约数代码:

long long  gcd(long long  c,long long  b)
{
    return b? gcd(b,c%b):c;
}