[:solved] two problems

Author: ppxyn1

climbing-stairs/ppxyn1.py

@@ -0,0 +1,20 @@
+# idea: DP
+# I'm not always sure how to approach DP problems. I just try working through a few examples step by step and then check that it would be DP.
+# If you have any suggestions for how I can come up with DP, I would appreciate your comments :)
+
+class Solution:
+    def climbStairs(self, n: int) -> int:
+        if n <= 2:
+            return n
+        dp = [0] * (n+1)
+        dp[2], dp[3] = 2, 3
+        
+        #for i in range(4, n): error when n=4       
+        for i in range(4, n+1):
+            dp[i] = dp[i-1] + dp[i-2]
+        
+        return dp[n]
+    
+    
+
+

valid-anagram/ppxyn1.py

@@ -0,0 +1,27 @@
+#idea: dictionary
+from collections import Counter 
+
+class Solution:
+    def isAnagram(self, s: str, t: str) -> bool:
+        s_dic = Counter(sorted(s))
+        t_dic = Counter(sorted(t))
+        print(s_dic, t_dic)
+        return s_dic==t_dic
+
+
+
+# Trial and Error
+'''
+When you call sorted() on a dictionary, it only extracts and sorts the keys,and the values are completely ignored.
+class Solution:
+    def isAnagram(self, s: str, t: str) -> bool:
+        s_dic = Counter(s)
+        t_dic = Counter(t)
+        print(s_dic, t_dic)
+        return sorted(s_dic)==sorted(t_dic)
+'''
+
+
+
+
+