Measure the Largest All-One Grid Rectangle
Company: Amazon
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: hard
Interview Round: Other
### Problem
The rectangular grid `bits` contains the characters `0` and `1`. Return the largest area of an axis-aligned rectangle made entirely of `1` cells.
Such a rectangle consists of consecutive rows and consecutive columns. Its area is the number of cells it contains. Return `0` if there is no `1` cell.
### Examples
**Example 1**
```text
Input: bits = [["1","1","0"],["1","1","1"],["0","1","1"]]
Output: 4
```
A two-by-two block of `1` cells has area `4`; no larger all-`1` rectangle exists.
**Example 2**
```text
Input: bits = [["0","0","0"],["0","0","0"]]
Output: 0
```
No cell can belong to a positive-area all-`1` rectangle.
### Constraints
- The grid has between `1` and `200` rows and between `1` and `200` columns.
- All rows have the same length.
- Every cell holds the character `0` or the character `1`.
Overview: Find the largest axis-aligned rectangle containing only one characters in a binary character grid, returning its cell area.
