1553. Minimum Number of Days to Eat N Oranges

There are n oranges in the kitchen and you decided to eat some of these oranges every day as follows:

• Eat one orange.
• If the number of remaining oranges n is divisible by 2 then you can eat n / 2 oranges.
• If the number of remaining oranges n is divisible by 3 then you can eat 2 * (n / 3) oranges.

You can only choose one of the actions per day.

Given the integer n, return the minimum number of days to eat n oranges.

class Solution {
public:
    int minDays(int n) {
        int day = 1;
        unordered_set<int> vis;
        queue<int> q;
        q.push(n);
        
        while(!q.empty()) {
            int sz = q.size();
            while(sz--) {
                auto num = q.front(); q.pop();
                if(!vis.count(num - 1)) {
                    if(num - 1 == 0) return day;
                    q.push(num - 1);
                    vis.insert(num-1);
                }
                if(num % 2 == 0 and !vis.count(num/2)) {
                    q.push(num/2);
                    vis.insert(num/2);
                }
                if(num % 3 == 0 and !vis.count(num/3)) {
                    q.push(num/3);
                    vis.insert(num/3);
                }
            }
            day++;
        }
        
        return day;
    }
};