2020-03-27

Author: JiayangWu

0820.单词的压缩编码/0820-单词的压缩编码.py

@@ -0,0 +1,36 @@
+class Trie(object):
+    def __init__(self):
+        """
+        Initialize your data structure here.
+        """
+        self.root = {}
+        self.char_cnt = 0 # 统计 a - z 字符个数
+        self.word_cnt = 0 # 统计结尾符 # 个数
+    def insert(self, word):
+        """
+        Inserts a word into the trie.
+        :type word: str
+        :rtype: None
+        """
+        node = self.root
+        for char in word: # word 入树
+            node = node.setdefault(char, {})
+
+        if not node: # not node 就代表当前 word 不是之前某一 word 的后缀        
+            self.word_cnt += 1 
+            self.char_cnt += len(word)
+        node["end"] = True 
+
+class Solution(object):
+    def minimumLengthEncoding(self, words):
+        """
+        :type words: List[str]
+        :rtype: int
+        """
+        ttree = Trie()
+
+        for word in sorted(words, key = lambda x:len(x), reverse = True):
+            # 按长度由大到小排序，再将每个 word 反向插入树
+            ttree.insert(word[::-1])
+        # print ttree.char_cnt, ttree.word_cnt
+        return ttree.char_cnt + ttree.word_cnt

0914.卡牌分组/0914-卡牌分组.py

@@ -1,36 +1,11 @@
 class Solution(object):
-    def hasGroupsSizeX( self,deck):
+    def hasGroupsSizeX(self, deck):
         """
         :type deck: List[int]
         :rtype: bool
         """
-        if len(deck) <=0:
-            return False
-        deck.sort()
-        print deck
-        a = deck[0]
-        count = deck.count(a)
-        if count < 2:
-            return False
-        for j in range(2, count +1):
-            if len(deck) % j != 0:
-                continue
-                print "invalid length",j,len(deck)
-            for i in range(0, len(deck),j):
-                temp = deck[i]
-                flag = 0
-                print i,temp
-                for k in range(i,i+j):
-                    if deck[k] != temp:
-                        flag = 1
-                        print "not the same",deck[k],temp
-                if flag == 1:
-                    break
-            if flag == 1:
-                continue
-            return True
-        return False
-
-
-        
-        
+        def gcd(a, b):
+            while b:
+                a, b = b, a % b 
+            return a
+        return functools.reduce(gcd, collections.Counter(deck).values()) >= 2