2019-08-25

Author: JiayangWu

1169.查询无效交易/1169-查询无效交易.py

@@ -0,0 +1,32 @@
+class Solution(object):
+    def invalidTransactions(self, transactions):
+        """
+        :type transactions: List[str]
+        :rtype: List[str]
+        """
+        recordByName = collections.defaultdict(list)
+        for trans in transactions:
+            name, time, amount, city = trans.split(",")
+            recordByName[name].append([name, int(time), int(amount), city])
+        
+        def convert(l): 
+            return l[0] + "," + str(l[1]) + "," + str(l[2]) + "," + l[3]
+        
+        res = set()
+        for name, rec in recordByName.items():
+            curRec = sorted(rec, key = lambda x:x[1])
+            
+            for i in range(len(curRec)):
+                if curRec[i][2] > 1000:
+                    res.add(convert(curRec[i]))
+                for j in range(i + 1, len(curRec)):
+                    
+                    if abs(curRec[j][1] - curRec[i][1]) > 60:  
+                        break
+                    if curRec[j][3] != curRec[i][3]:
+                        res.add(convert(curRec[i]))
+                        res.add(convert(curRec[j]))
+        return res
+                        
+                        
+                

1170.比较字符串最小字母出现频次/1170-比较字符串最小字母出现频次.py

@@ -0,0 +1,28 @@
+class Solution(object):
+    def numSmallerByFrequency(self, queries, words):
+        """
+        :type queries: List[str]
+        :type words: List[str]
+        :rtype: List[int]
+        """
+        
+        def func(word):
+            for char in "abcdefghijklmnopqrstuvwxyz":
+                if char in word:
+                    return word.count(char)
+            return 0
+        
+        def func2(word):
+            record = collections.Counter(word)
+            return record[min(record.keys())]
+        
+        
+        words_count = sorted(map(func2, words))
+        queries_count = map(func2, queries)
+        # print words_count, queries_count
+        ans = []
+        for query in queries_count:
+            index = bisect.bisect(words_count, query) #bisect可以迅速找出有index个数 <= query
+            ans.append(len(words_count) - index)# 减法找有多少个数比query大
+        return ans
+            

1171.从链表中删去总和值为零的连续节点/1171-从链表中删去总和值为零的连续节点.py

@@ -0,0 +1,26 @@
+# Definition for singly-linked list.
+# class ListNode(object):
+#     def __init__(self, x):
+#         self.val = x
+#         self.next = None
+
+class Solution(object):
+    def removeZeroSumSublists(self, head):
+        """
+        :type head: ListNode
+        :rtype: ListNode
+        """
+        dummy = ListNode(-1)
+        dummy.next = head
+        
+        record = {0:dummy}
+        pre_sum = 0
+        
+        while head:
+            pre_sum += head.val
+            if pre_sum in record:
+                record[pre_sum].next = head.next
+            else:
+                record[pre_sum] = head
+            head = head.next
+        return dummy.next

1172.餐盘栈/1172-餐盘栈.py

@@ -0,0 +1,58 @@
+from heapq import *
+class DinnerPlates(object):
+    def __init__(self, capacity):
+        """
+        :type capacity: int
+        """
+        self.stack = []
+        self.c = capacity
+        self.idx = [] #用于存放有空位的栈的下标
+
+    def push(self, val):
+        """
+        :type val: int
+        :rtype: None
+        """
+        if self.idx:
+            index = heappop(self.idx) #找最小的空的栈的下标
+            self.stack[index].append(val) #插入val
+            if len(self.stack[index]) < self.c: #如果插了之后还没满，就把这个空的栈的下标放进self.idx
+                heappush(self.idx, index)
+        else: #现在所有栈都满了，只能新增一个栈在末尾
+            self.stack.append([val])
+            if self.c > 1:
+                self.idx.append(len(self.stack) - 1)
+            
+
+    def pop(self):
+        """
+        :rtype: int
+        """
+        while self.stack and not self.stack[-1]:
+            self.stack.pop()
+        if not self.stack: #所有的栈都是空的
+            return -1
+        else:
+            if len(self.stack[-1]) == self.c: #如果本来是满的栈
+                heappush(self.idx, len(self.stack) - 1) #现在要变成有空位的栈了
+            return self.stack[-1].pop()
+            
+    def popAtStack(self, index):
+        """
+        :type index: int
+        :rtype: int
+        """
+        if index >= len(self.stack): #下标越界
+            return -1
+        else:
+            s = self.stack[index] # 把下标为index的栈取出来
+            if len(s) == self.c: #如果这个栈本来是满的
+                heappush(self.idx, index) #马上要变空了
+            return s.pop() if s else -1 #如果这个栈是空的，返回-1， 否则返回pop
+
+
+# Your DinnerPlates object will be instantiated and called as such:
+# obj = DinnerPlates(capacity)
+# obj.push(val)
+# param_2 = obj.pop()
+# param_3 = obj.popAtStack(index)