问题 A: Least Common Multiple

题目描述

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.

输入

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.

输出

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

样例输入

2
2 3 5
3 4 6 12

样例输出

15
12

题意 有T组数据 每组首先给一个n 然后有n个数 问这个n个数的最小公倍数是多少

#include<bits/stdc++.h>

using namespace std;
int gcd(int a,int b)
{
    if(b==0) return a;
    return gcd(b,a%b);
}
int main()
{
    int T;
    scanf("%d",&T);
    while(T--){
        int n;
        scanf("%d",&n);
        int d=1;//小技巧 可以把d设置成1
        for(int i=0;i<n;i++){
            int x;
            scanf("%d",&x);
            d=d/gcd(d,x)*x;//第一次时 gcd=1  这种写法防止溢出
        }
        printf("%d\n",d);
    }
    return 0;
}