Pascal’s Triangle

The first row is [1]. Each later row starts and ends with 1. Every interior entry is the sum of the two entries immediately above it. Return the first rows rows, beginning with the single 1.

Implement pascals_triangle(rows).

Input

rows: How many rows to generate.

Output

Return a list of rows, starting at the top; each row is a list of integers.

सीमाएँ

0 ≤ rows ≤ 60. Every entry fits a signed 64-bit integer. Zero rows returns an empty list.

उदाहरण

इनपुट:
rows = 4

अपेक्षित आउटपुट:
expected = [
    [1],
    [1, 1],
    [1, 2, 1],
    [1, 3, 3, 1]
]

इनपुट:
long long rows = 4;

अपेक्षित आउटपुट:
std::vector<std::vector<long long>> expected = {
    {1},
    {1, 1},
    {1, 2, 1},
    {1, 3, 3, 1}
};

इनपुट:
long rows = 4;

अपेक्षित आउटपुट:
long[][] expected = new long[][] {
    new long[] {1},
    new long[] {1, 1},
    new long[] {1, 2, 1},
    new long[] {1, 3, 3, 1}
};

इनपुट:
rows = 0

अपेक्षित आउटपुट:
expected = []

इनपुट:
long long rows = 0;

अपेक्षित आउटपुट:
std::vector<std::vector<long long>> expected = {};

इनपुट:
long rows = 0;

अपेक्षित आउटपुट:
long[][] expected = new long[][] {};

संदर्भ

यह चुनौती CodeUtility के लिए अनुकूलित की गई है। ऊपर दिए गए स्टेटमेंट और सीमाओं का पालन करें।

• Pascal's Triangle