2136 Problem A Least Common Multiple

問題 A: Least Common Multiple

時間限制: 1 Sec  內存限制: 32 MB
 

題目描述

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.

輸入

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.

輸出

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

樣例輸入

2
2 3 5
3 4 6 12

樣例輸出

15
12

經驗總結

題目其實就是求最小公倍數，原理就是利用最大公約數，A*B/(gcd(A,B) )，多個數原理相同~~

AC代碼

#include <cstdio>
int gcd(int a,int b)
{
	return !b?a:gcd(b,a%b);
}
int main()
{
	int n,m;
	while(~scanf("%d",&n))
	{
		for(int i=0;i<n;i++)
		{
			scanf("%d",&m);
			int first,d;
			scanf("%d",&first);
			for(int j=0;j<m-1;j++)
			{
				int temp;
				scanf("%d",&temp);
				d=gcd(first,temp);
				if(d==0)
				{
					first=0;
					break;
				}
				first=first/d*temp;
			}
			printf("%d\n",first);
		}
	}
    return 0;
}