I have a matrix like this:

```
0 1 0 0 1 0
1 0 1 0 1 0
0 1 0 1 0 0
0 0 1 0 1 1
1 1 0 1 0 0
0 0 0 1 0 0
```

How can I define a matrix in Ruby, and then search through it?

I would like to write a program which searches through all rows and returns rows with the highest sum of "1".

# Best How To :

Quick way to define a matrix in Ruby:

```
Array.new 6, Array.new(6, 0)
# => [
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0]
]
```

The above code initializes an array with 6 items and defaults their values to the 2nd argument which is another array with 6 items and default values of 0.

In other more imperative languages you would use nested loops:

```
matrix = []
for x in [0,1,2,3,4,5]
for y in [0,1,2,3,4,5]
matrix[x] ||= [] # create the row as an empty array
matrix[x] << y # push the y value to it
end
end
# matrix is now:
# => [
[0, 1, 2, 3, 4, 5],
[0, 1, 2, 3, 4, 5],
[0, 1, 2, 3, 4, 5],
[0, 1, 2, 3, 4, 5],
[0, 1, 2, 3, 4, 5],
[0, 1, 2, 3, 4, 5]
]
```

To search through the matrix and find the row with greatest sum:

```
greatest_sum_row_index = 0
greatest_sum = 0
matrix.each_with_index do |row, i|
# row.inject(:+) is a shortcut to adding each int in the array and returning the sum
sum = row.inject(:+)
if sum > greatest_sum
greatest_sum = sum
greatest_sum_row_index = i
end
end
# highest_row is now the index of the greatest sum row
matrix[greatest_sum_row_index] # returns the row with the greatest sum
```