Leetcode 74: Search a 2D Matrix

*Purpose:*

* This code aims to efficiently determine whether a given integer `target` exists within a 2D matrix of integers.
* The matrix is assumed to be sorted in ascending order, both row-wise and column-wise.

*Explanation:*

1. *Initialization:*
- `m`: Stores the number of rows in the matrix.
- `n`: Stores the number of columns in the matrix.
- `s`: Represents the starting index for binary search (0).
- `e`: Represents the ending index for binary search (total number of elements - 1).

2. *Binary Search:*
- The code employs a binary search approach to efficiently locate the target within the matrix.
- In each iteration:
- `mid`: Calculates the middle index within the current search range.
- `row`: Calculates the row index of the element at the `mid` index.
- `col`: Calculates the column index of the element at the `mid` index.
- *Comparison:*
- If `matrix[row][col]` is equal to `target`, the function returns `true` (target found).
- If `matrix[row][col]` is less than `target`, the search range is narrowed down to the right half of the current range (`s = mid + 1`).
- If `matrix[row][col]` is greater than `target`, the search range is narrowed down to the left half of the current range (`e = mid - 1`).

3. *Not Found:*
- If the `while` loop completes without finding the target, the function returns `false` (target not found).

*Key Idea:*

* The code effectively treats the 2D matrix as a 1D array.
* By calculating the `row` and `col` indices from the `mid` index, it can efficiently perform binary search on the flattened representation of the matrix.

*Example:*

Consider the following matrix:

```
[
[1, 3, 5, 7],
[10, 11, 16, 20],
[23, 30, 34, 50]
]
```

The code would effectively search through this matrix as if it were a single sorted array:

```
[1, 3, 5, 7, 10, 11, 16, 20, 23, 30, 34, 50]
```

I hope this explanation is helpful! Feel free to ask if you have any further questions.



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