feat: add 119

Author: Blankj

README.md

@@ -36,6 +36,8 @@
 |110|[Balanced Binary Tree][110]|Tree, Depth-first Search|
 |111|[Minimum Depth of Binary Tree][111]|Tree, Depth-first Search, Breadth-first Search|
 |112|[Path Sum][112]|Tree, Depth-first Search|
+|118|[Pascal's Triangle][118]|Array|
+|119|[Pascal's Triangle II][119]|Array|
 
 
 ## Medium
@@ -87,6 +89,8 @@
 [110]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/110/README.md
 [111]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/111/README.md
 [112]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/112/README.md
+[118]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/118/README.md
+[119]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/119/README.md
 
 [008]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/008/README.md
 [019]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/019/README.md

note/119/README.md

@@ -0,0 +1,43 @@
+# [Pascal's Triangle II][title]
+
+## Description
+
+Given an index *k*, return the *k*th row of the Pascal's triangle.
+
+For example, given *k* = 3,
+Return `[1,3,3,1]`.
+
+**Note:**
+Could you optimize your algorithm to use only *O*(*k*) extra space?
+
+**Tags:** Array
+
+
+## 思路
+
+题意是指定输出帕斯卡尔三角形的某一行，模拟即可，优化后的代码如下所示。
+
+``` java
+class Solution {
+ public List<Integer> getRow(int rowIndex) {
+ List<Integer> res = new ArrayList<>();
+ for (int i = 0; i <= rowIndex; ++i) {
+ res.add(1);
+ for (int j = i - 1; j > 0; --j) {
+ res.set(j, res.get(j - 1) + res.get(j));
+ }
+ }
+ return res;
+ }
+}
+```
+
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我GitHub上的LeetCode题解：[awesome-java-leetcode][ajl]
+
+
+
+[title]: https://leetcode.com/problems/pascals-triangle-ii
+[ajl]: https://github.com/Blankj/awesome-java-leetcode