2507. Smallest Value After Replacing With Sum of Prime Factors

You are given a positive integer n.

Continuously replace n with the sum of its prime factors.

• Note that if a prime factor divides n multiple times, it should be included in the sum as many times as it divides n.

Return the smallest value n will take on.

class Solution {
public:
    int smallestValue(int n) {
        while(true) {
            int now = 0;
            int origin = n;
            for(int i = 2; i * i <= n; i++) {
                if(n % i) continue;
                while(n % i == 0) {
                    n /= i;
                    now += i;
                }
            }
            if(n != 1) {
                now += n;
            }
            if(origin > now) n = now;
            else return now;
        }
        return -1;
    }
};