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LeetCode-232 Implement Queue using Stacks : Implement a first in first out (FIFO) queue using only two stacks. The implemented queue should support all the functions of a normal queue (push, peek, pop, and empty). note : sub선입선출 :::python class MyQueue: def init(self): self.temp = collections.deque() def push(self, x: int) -> None: self.temp.append(x) def pop(self) -> int: return self.temp.pople..

LeetCode-225 Implement Queue using Stacks : Implement a last-in-first-out (LIFO) stack using only two queues. The implemented stack should support all the functions of a normal stack note : last-in-first-out (LIFO) Answer :::python class MyStack: def init(self): self.temp = [] def push(self, x: int) -> None: self.temp.append(x) def pop(self) -> int: return self.temp.pop() def top(self) -> int: r..

LeetCode-739 Daily Temperature : 몇 일 후 기온이 오를까? note : Answer :::python class Solution: def dailyTemperatures(self, temperatures: List[int]) -> List[int]: out = [] left, right = 0, 0 while left != len(temperatures)-1: day = 0 check = 0 while right temperatures[stack[-1]]: last = stack.pop() answer[last] = i - last stack.append(i) return answer Result : 1352ms Memory: 28.6mb

LeetCode-316 Remove Duplicate Letters : Given a string s, remove duplicate letters so that every letter appears once and only once. You must make sure your result is the smallest in lexicographical order among all possible results. note :Answer :::python class Solution: def removeDuplicateLetters(self, s: str) -> str: for char in sorted(set(s)): suffix = s[s.index(char):] if set(s)==set(suffix):..

LeetCode-20 Valid Parentheses : Given a string s containing just the characters (, ), {, }, [ and ], determine if the input string is valid. note : s consists of parentheses only ()[]{}Answer :::python class Solution: def isValid(self, s: str) -> bool: valid = [] dict_valid = { "}":"{", "]":"[", ")":"(" } for l in s: if l not in dict_valid: valid.append(l) elif not valid or dict_valid[l] != vali..

LeetCode-92 Reverse Linked List II : Given the head of a singly linked list and two integers left and right where left

LeetCode-24 swap-nodes-in-pairs_2 : Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes note : only nodes themselves may be changed.MyAnswer :::python # Definition for singly-linked list. # class ListNode: # def init(self, val=0, next=None): # self.val = val # self.next = next class Solution: def swap..

LeetCode-24 swap-nodes-in-pairs : Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes note : only nodes themselves may be changed.MyAnswer :::python # Definition for singly-linked list. # class ListNode: # def init(self, val=0, next=None): # self.val = val # self.next = next class Solution: def swapPa..