问题陈述

Problem Statement:

Find and return the nth row of Pascal's triangle in the form a list. n is 0-based.

For exmaple, if n = 4, then output = [1, 4, 6, 4, 1].

To know more about Pascal's triangle: https://www.mathsisfun.com/pascals-triangle.html

python实现

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def next_row(current_row):
    row = [1]
    for i in range(len(current_row)):
        if i == len(current_row)-1:
            break
        row.append(current_row[i] + current_row[i+1])
    row.append(1)
    return row
def nth_row_pascal(num_row):
    if num_row == 0:
        return [1]
    if num_row == 1:
        return [1, 1]
    n = 2
    current_row = [1, 1]
    while n != num_row:
        n += 1
        current_row = next_row(current_row)
    return next_row(current_row)

测试代码： 

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def test_function(test_case):
    n = test_case[0]
    solution = test_case[1]
    output = nth_row_pascal(n)
    if solution == output:
        print("Pass")
    else:
        print("Fail")

n = 0
solution = [1]
test_case = [n, solution]
test_function(test_case)

n = 1
solution = [1, 1]
test_case = [n, solution]
test_function(test_case)

n = 2
solution = [1, 2, 1]
test_case = [n, solution]
test_function(test_case)

n = 3
solution = [1, 3, 3, 1]
test_case = [n, solution]
test_function(test_case)

n = 4
solution = [1, 4, 6, 4, 1]
test_case = [n, solution]
test_function(test_case)

print(nth_row_pascal(5))