花花酱 LeetCode 118. Pascal's Triangle

Given an integer numRows, return the first numRows of Pascal’s triangle.

In Pascal’s triangle, each number is the sum of the two numbers directly above it as shown:

Example 1:

Input: numRows = 5
Output: [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]

Example 2:

Input: numRows = 1
Output: [[1]]

Constraints:

Solution: Simulation

Time complexity: O(n²)
Space complexity: O(n²)

// Author: Huahua

class Solution {

public:

vector<vector<int>> generate(int numRows) {

vector<vector<int>> ans(numRows);

for (int i = 0; i < numRows;++i) {

ans[i].resize(i + 1);

ans[i][0] = ans[i][i] = 1;

for (int j = 1; j < i; ++j)

ans[i][j] = ans[i-1][j] + ans[i-1][j-1];

}

return ans;

}

请尊重作者的劳动成果，转载请注明出处！花花保留对文章／视频的所有权利。
如果您喜欢这篇文章／视频，欢迎您捐赠花花。
If you like my articles / videos, donations are welcome.

Buy anything from Amazon to support our website
您可以通过在亚马逊上购物（任意商品）来支持我们

Paypal

Venmo
huahualeetcode

微信打赏