HDU 1019 Least Common Multiple

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

 

Sample Input2
3 5 7 15
6 4 10296 936 1287 792 1 Sample Output

10510296

#include <iostream>using namespace std;//用long long int 可以防止兩個過大的int相乘溢出long long int gcd(long long int a,long long int b){if(b == 0) return a;else return gcd(b,a%b);}long long int lcm(long long int a,long long int b){return a*b/gcd(a,b);}int main(){int n,cnt,num,result;cin >> n;while(--n+1){cin >> cnt;result = 1;while(--cnt+1){cin >> num;result = lcm (num,result);}cout << result <<endl;}    return 0;}