Here you will create the classic [Pascal's triangle](https://en.wikipedia.org/wiki/Pascal%27s_triangle).
Your function will be passed the depth of the triangle and you code has to return the corresponding pascal triangle up to that depth.

The triangle should be returned as a nested array.

for example:
```python
pascal(5) # should return [[1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1]]
```

To build the triangle, start with a single 1 at the top, for each number in the next row you just take the two numbers above it and add them together (except for the edges, which are all `1`), e.g.:
```
              [1]
            [1   1]
          [1   2   1]
        [1   3   3   1]
```

Source: codewars | Difficulty: EASY
Tags: Data structures

Starter code: def pascal(p):
	

Solutions:
def pascal(p):
	triangle = [[1]]
	for _ in range(p - 1):
		to_sum = list(zip([0] + triangle[-1], triangle[-1] + [0]))
		triangle.append(list(map(sum, to_sum)))
	return triangle


def pascal(p):

	def create_row(n):
		row = [1]
		for k in range(n):
			row.append(row[k] * (n - k) / (k + 1))
		return row
	tri = []
	for row in range(p):
		tri.append(create_row(row))
	return tri


def pascal(p):
	t = [[1]]
	for _ in range(2, p + 1):
		t.append([1] + [a + b for (a, b) in zip(t[-1][:-1], t[-1][1:])] + [1])
	return t


def pascal(p):
	ans = []
	for i in range(p):
		row = []
		for k in range(i + 1):
			if k == 0 or k == i:
				row.append(1)
			else:
				row.append(ans[i - 1][k - 1] + ans[i - 1][k])
		ans.append(row)
	return ans


from math import factorial

def pascal(p):
	return [[int(factorial(p) / (factorial(k) * factorial(p - k))) for k in range(0, p + 1)] for p in range(0, p)]


def pascal(p):
	if p == 1:
		return [[1]]
	output = [[1], [1, 1]]
	last = [1, 1]
	count = 2
	while count < p:
		new = []
		new.append(1)
		for i in range(count - 1):
			new.append(last[i] + last[i + 1])
		new.append(1)
		output.append(new)
		last = new
		count += 1
	return output


def pascal(p):
	(row, res) = ([1], [])
	for x in range(max(p, 0)):
		res.append(row)
		row = [l + r for (l, r) in zip(row + [0], [0] + row)]
	return res


def pascal(p):
	l = [[1]]
	for index in range(p - 1):
		values = []
		for (i, j) in enumerate(l[index][:-1]):
			values.append(j + l[index][i + 1])
		l.append(l[index][:1] + values + l[index][-1:])
	return l