Menene stack kuma mene ake amfani da shi?

Question

Accepted Answer

**Stack** shine **LIFO** (Last-In, First-Out) tara: abin da aka soka na ƙarshe shi ne na farko a fitarwa. Ka ɗauki kawai **top** ko waje.

## Ayyuka

```text
push(3)   push(7)   pop()->7   peek()->3
 [ 3 ]     [ 7 ]      [ 3 ]      [ 3 ]
           [ 3 ]                 top
            top
```

## Misali

```python
stack = []
stack.append('a')   # push
stack.append('b')   # push
top = stack[-1]     # peek -> 'b'
stack.pop()         # pop  -> 'b'
```

Duk ayyuka **O(1)** ne lokacin da ƙaƙƙarfan jerin ko linked list ya gabatar da shi.

| Aiki | Lokaci |
|---|---|
| push | O(1) |
| pop | O(1) |
| peek | O(1) |

## Sanannun amfani

- **Function call stack** — lura da kira masu aiki da siggaye na gida.
- **Undo/redo** — soka kila aiki; fitarwa don undo.
- **Tantance/sharewa jerin — daidaitawa da maɓugga, canza infix zuwa postfix.
- **Backtracking & DFS** — tuna inda za ka koma.

## Dalilin da yasa hakan yake da muhimmanci

Stack yana aiki da tunanin "yi mafi sabon abu da farko," wanda aka ga a ko'ina daga gajerewa zuwa buɗin karshe na browser.

Sanin tunanin LIFO nan da nan yana nuna stack, wanda sau da yawa yana juyar da matsalar mai daraja zuwa wasu layin push/pop masu tsabta.