Pascal's Triangle II
【题目】
Given a non-negative index k where k ≤ 33, return the kth index row of the Pascal's triangle.
Note that the row index starts from 0.
(翻译:给定一个非负索引 k,其中 k ≤ 33,返回杨辉三角的第 k 行。)
In Pascal's triangle, each number is the sum of the two numbers directly above it.
(在杨辉三角中,每个数是它左上方和右上方的数的和。)
Example:
代码语言:javascript复制Input: 3
Output: [1,3,3,1]
【分析】
只是我上一篇博客题目的简单变形,此题更为简单,还是用ArrayList 暴力求解,Java实现代码如下:
代码语言:javascript复制class Solution {
public List<Integer> getRow(int rowIndex) {
List<Integer> row = new ArrayList<>();
if (rowIndex < 0) return row;
for (int i = 0; i < rowIndex 1; i ) {
row.add(0, 1);
for (int j = 1; j < row.size() - 1; j ) {
row.set(j, row.get(j) row.get(j 1));
}
}
return row;
}
}