Initialization

The solution initializes an integer variable count to 0, which will keep track of the current directory level.

Base Cases

The solution handles two base cases within the loop: If the log is "../", it checks if the count is greater than 0 and decrements it if true. If the log is "./", it does nothing as it represents staying in the current directory.

State Transition

For each log entry: If the log is "../", decrement the count if it is greater than 0. If the log is "./", do nothing. For any other log entry, increment the count.

Complexity

Time complexity: O(n). Space complexity: O(1).

class Solution {
public:
    int minOperations(vector<string>& logs) {
        std::ios_base::sync_with_stdio(false);
        std::cin.tie(NULL);
        int count = 0;
        for(int i = 0; i < logs.size(); ++i) {
            if (logs[i] == "../") {
                if (count > 0) {
                    --count;
                }
            } else if (logs[i] != "./") {
                ++count;
            }
        }
        return count;
    }
};