Hdu 1019 Least Common Multiple (数论)

题目

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

代码实现

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<iostream>
using namespace std;
//所有数用欧几里得简化后求最小公倍数
typedef long long ll;
const int maxn = 10005;
int t, n, m, a;
int gcd (int a,int b) {
    if (b==0) return a;
    return gcd (b,a%b);
}
int main () {
    cin>>t;
    while (t--) {
      ll ans=1;
      cin>>n;
      for (int i=1;i<=n;i++) {
          cin>>m;
          ans=ans*m/gcd(m,ans);
      }
      cout<<ans<<endl;
    }
    return 0;
}