Rearrange balls

gistfile1.txt

vector<string> rearrange(vector<int>& baskets);

// [ 2 , 1 , 4 , 5 , 3 , empty_basket ]

vector<int> baskets = {2,1,4,5,3,0};
vector<string> commands = rearrange(baskets);
for (string command : commands) {
  cout << command << endl;
}

/*
move 2 to [5]
move 1 to [0]
move 2 to [1]
move 4 to [5]
move 3 to [2]
move 5 to [4]
move 4 to [3]
*/

    vector<string> rearrange(vector<int>& baskets) {

        vector<string> commands;
        int i = 0, last = (int)baskets.size() - 1, empty = last, done = 0;

        while (done < (int)baskets.size() - 1) {

            // 1. if empty is at the last, find any ball in a wrong basket and move it to empty (swap it with the empty)
            // 2. if empty is not the last, move the correct ball (empty+1) to the current empty basket (swap it with the empty)
            if ((empty == last && baskets[i] != i + 1) ||
                (empty != last && baskets[i] == empty + 1)) {

                // swap brackets[i], brackets[empty]
                commands.push_back("move " + to_string(baskets[i]) + " to [" + to_string(empty) + "]");
                baskets[empty] = baskets[i];
                baskets[i] = 0;

                // check if empty is filled correctly
                if (baskets[empty] == empty + 1) {
                    done++;
                }
                empty = i;
            }
            i = (i + 1) % (int)baskets.size();
        }

        return commands;
    }