feat: add 118

Author: Blankj

note/118/README.md

@@ -0,0 +1,57 @@
+# [Pascal's Triangle][title]
+
+## Description
+
+Given *numRows*, generate the first *numRows* of Pascal's triangle.
+
+For example, given *numRows* = 5,
+Return
+
+```
+[
+     [1],
+    [1,1],
+   [1,2,1],
+  [1,3,3,1],
+ [1,4,6,4,1]
+]
+```
+
+**Tags:** Array
+
+
+## 思路
+
+题意是给出行数，输出帕斯卡尔三角形，很简单的模拟，就不多说了。
+
+``` java
+class Solution {
+    public List<List<Integer>> generate(int numRows) {
+        if (numRows == 0) return Collections.emptyList();
+        List<List<Integer>> list = new ArrayList<>();
+        for (int i = 0; i < numRows; ++i) {
+            List<Integer> sub = new ArrayList<>();
+            for (int j = 0; j <= i; ++j) {
+                if (j == 0 || j == i) {
+                    sub.add(1);
+                } else {
+                    List<Integer> upSub = list.get(i - 1);
+                    sub.add(upSub.get(j - 1) + upSub.get(j));
+                }
+            }
+            list.add(sub);
+        }
+        return list;
+    }
+}
+```
+
+
+## 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
+[ajl]: https://github.com/Blankj/awesome-java-leetcode