帕斯卡三角形

lc118. Pascal's Triangle.py

@@ -0,0 +1,33 @@
+class Solution:
+    def generate(self, numRows):
+        """
+        :type numRows: int
+        :rtype: List[List[int]]
+        """
+        if not numRows:
+            return []
+        # elif numRows == 1:
+        #     return [[1]]
+        # elif numRows == 2:
+        #     return [[1], [1, 1]]
+
+        # res = [[1], [1, 1]]
+        res = [[1]]
+
+        for i in range(1, numRows):
+            tem = []
+            tem.append(1)
+
+            for j in range(1, i):
+
+                x = res[i - 1][j] + res[i - 1][j - 1]
+                tem.append(x)
+            tem.append(1)
+            res.append(tem)
+
+        return res
+
+
+num = 5
+s = Solution()
+print(s.generate(num))