Create yang_hui_triangle.py

yingl · web-flow · commit 712485b4709a · 2018-04-08T22:01:37.000+08:00
diff --git a/yang_hui_triangle.py b/yang_hui_triangle.py
@@ -0,0 +1,21 @@
+class Solution:
+    """
+    @param n: a Integer
+    @return: the first n-line Yang Hui's triangle
+    """
+    def calcYangHuisTriangle(self, n):
+        # write your code here
+        if n == 0:
+            return []
+        else:
+            ret = [[1]]
+            for i in range(1, n):
+                prev_level = ret[-1]
+                new_level = [1]
+                for i in range(len(prev_level) - 1):
+                    new_level.append(prev_level[i] + prev_level[i + 1])
+                new_level.append(1)
+                ret.append(new_level)
+            return ret
+
+# easy: http://lintcode.com/zh-cn/problem/yang-hui-triangle/
