Update 413.等差数列划分.py

linwt · web-flow · commit 8931051427ed · 2019-06-05T22:48:07.000+08:00
diff --git a/leetcode/413.等差数列划分.py b/leetcode/413.等差数列划分.py
@@ -1,9 +1,8 @@
-# 动态规划，dp[i]记录以元素A[i]结尾的等差数列的个数
-# 每增加一个元素，如果与前面数组形成等差数列，则以该元素结尾的等差数列个数为前一元素结尾的等差数列个数加1
+# 动态规划，dp[i]记录增加元素A[i]与前面构成等差数列时，新增的等差数列子数组个数，且个数刚好为前一状态新增个数加1
 class Solution(object):
     def numberOfArithmeticSlices(self, A):
         dp = [0]*len(A)
         for i in range(2, len(A)):
             if A[i] - A[i-1] == A[i-1] - A[i-2]:
                 dp[i] = dp[i-1] + 1
-        return sum(dp)
+        return sum(dp)
