## Question 1
Given these values as input, which matrix represents the state of the matrix on day 4? 

**Note:** In the options, $1$ represents water.

$rows = 3$

$cols = 3$

$water\_cells = [~[3, 2], ~[1, 3], ~[2, 2], ~[3, 1], ~[1, 1], ~[1, 2], ~[2, 3], ~[3, 3], ~[2, 1]]~$
### Options

1. | 0 | 0 | 0 |
-
| 0 | 0 | 0 |
-
| 0 | 0 | 0 |
-
Incorrect
None of the cells have been flooded.
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2. | 1 | 0 | 1 |
-
| 0 | 1 | 0 |
-
| 1 | 1 | 0 |
-
Incorrect
Only four cells may be flooded by day 4.
----------------------------

3. | 0 | 0 | 1 |
-
| 0 | 1 | 0 |
-
| 1 | 1 | 0 |
-
Correct
* On day 1, as per the `water_cells` array, the cell in the $3^{rd}$ row and the $2^{nd}$ column, [3, 2], will get flooded.

* On day 2, the cell in the $1^{st}$ row and the $3^{rd}$ column, [1, 3], will get flooded.

* On day 3, the cell in the $2^{nd}$ row and the $2^{nd}$ column, [2, 2], will get flooded.

* On day 4, the cell in the $3^{rd}$ row and the $1^{st}$ column, [3, 1], will get flooded.
----------------------------

4. | 1 | 1 | 0 |
-
| 0 | 1 | 0 |
-
| 0 | 0 | 1 |
-
Incorrect
The $1^{st}$ row is the top row, not the bottom row.
----------------------------

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## Question 2
Given these values as input, which row will be the first to be completely flooded?

$rows = 4$

$cols = 3$

$water\_cells = [~[2, 3], ~[1, 1], ~[2, 1], ~[4, 3], ~[3, 3], ~[4, 1], ~[4, 2], ~[1, 3], ~[3, 2], ~[1, 2], ~[2, 2], ~[3, 1]~]$
### Options

1. 1
Incorrect

----------------------------

2. 2
Incorrect

----------------------------

3. 3
Incorrect

----------------------------

4. 4
Correct
On the seventh day, all three cells in the 4th row are flooded. No other row is completely flooded at this point.
----------------------------

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## Question 3
What will be the last day where we can still cross the matrix, from top to bottom, if the following values are given as input?

$rows = 3$

$cols = 3$

$water\_cells = [~[3, 2], ~[1, 3], ~[2, 2], ~[3, 1], ~[1, 1], ~[1, 2], ~[2, 3], ~[3, 3], ~[2, 1]]~$
### Options

1. 9
Incorrect

----------------------------

2. 6
Incorrect

----------------------------

3. 3
Correct
The last day where it is possible to cross the matrix from top to bottom is on day 3.

* On day 1, as per the `water_cells` array, the cell in the 3rd row and the 2nd column, [3, 2], will get flooded, but we can cross the matrix from top to bottom.

* On day 2, the cell in the 1st row and the 3rd column, [1, 3], will get flooded, but we can cross the matrix from top to bottom.

* On day 3, the cell in the 2nd row and the 2nd column, [2, 2], will get flooded, but we can cross the matrix from top to bottom.

* On day 4, the cell in the 3rd row and the 1st column, [3, 1], will get flooded, so now we can't cross the matrix from top to bottom.
----------------------------

4. 1
Incorrect

----------------------------

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## Question 4
What will be the last day where we can still cross the matrix, from top to bottom, if the following values are given as input?

$rows = 2$

$cols = 4$

$water\_cells = [~[1, 2], ~[1, 4], ~[2, 1], ~[1, 1], ~[2, 4], ~[1, 3], ~[2, 3], ~[2, 2]~]$
### Options

1. 5
Correct
On the 1st day, cell [1, 2] will be filled with water, and we can move from top to the bottom row. On the 2nd day, cell [1, 4] will be filled with water, and we can move from top to the bottom row. On the 3rd, 4th, and 5th days, cells [2, 1], [1, 1], and [2, 4] will be filled and we can still move from top to the bottom row. However, on the 6th day, cell [1, 3] will be filled with water and it is not possible to move from top to the bottom row. Therefore, 5 was the last day where we could still cross.
----------------------------

2. 6
Incorrect

----------------------------

3. 7
Incorrect

----------------------------

4. 8
Incorrect

----------------------------

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