simulate the change directory command

Question

# Simulate the `cd` command

**Difficulty:** Medium | **Tags:** Strings, Stack, Simulation

Implement a small command-line program to simulate the behavior of the `cd` (Change Directory) command. The program should support both relative and absolute path changes.

**Requirements:**
- Support switching from the root directory `root/` to a subdirectory like `root/subfolder/`
- Support navigating to parent directories using `..`
- Support absolute paths (starting from `root/`)
- Handle edge cases: invalid paths, navigating above root, empty input
- Return the resulting path after each `cd` call

**Example:**
```
cd("root/", "subfolder")      → "root/subfolder"
cd("root/subfolder", "..")    → "root"
cd("root/a/b", "../../c")     → "root/c"
cd("root/", "/root/x/y")      → "root/x/y"   (absolute)
cd("root/", "..")             → "root"        (cannot exceed root)
```

---

## Question

```python
def cd(current_path: str, target: str) -> str:
    """
    Simulates the 'cd' command.

Args:
        current_path: The current directory as a string (e.g. "root/a/b")
        target: The target path to navigate to. Can be:
                - Relative: "subfolder", "..", "../../x"

Accepted Answer

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