CF - Orac & LCM

Official Editorial

Solution

For each prime, the second-to-lowest exponent of the prime that occurs in any of the numbers in the input is the exponent of this prime that will appear in the final answer.

Here's a short solution that accomplishes this without explicitly computing any prime factorizations!

1#include <bits/stdc++.h>
2using namespace std;
3 
4using ll = long long;
5
6ll a,b; 
7// a stores minimum exponents
8// b stores second minimum exponents
9int n;
10

If it's hard to understand what exactly this code is doing at first glance, a good first step is to simulating the code in the case where each $a_i$ is a power of the same prime (say, $2^k$). If the algorithm works for this case, then it will also work in the general case since the contributions of different primes are computed independently and multiplied together.