C/C++
LeetCode: 5-Longest Palindromic Substring 解題紀錄
題目
Given a string s, return the longest palindromic substring in s.
Example:
Input: s = "babad"
Output: "bab"
Note: "aba" is also a valid answer.
題目給定一個輸入字串,而我們要在這個字串中,找到最大的『回文子字串』。回文(palindromic)是什麼意思呢?就是即使字串顛倒過來也是相同的,就好比範例中的 bab 一樣,顛倒過來同樣是 bab。
不過這題要求回傳的答案只要是任一最長的回文子字串即可,不需要回傳『全部』的答案,也算是某種程度的佛心來著?(雖說只要將最長的都記錄起來就行了)
Read More »LeetCode: 5-Longest Palindromic Substring 解題紀錄LeetCode: 6-ZigZag Conversion 解題紀錄
題目
The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)
P A H N
A P L S I I G
Y I R
And then read line by line: "PAHNAPLSIIGYIR"
Write the code that will take a string and make this conversion given a number of rows:
string convert(string s, int numRows);
Example:
Input: s = "PAYPALISHIRING", numRows = 4
Output: "PINALSIGYAHRPI"
Explanation:
P I N
A L S I G
Y A H R
P I
這個題目給定輸入一個字串以及行高 numRows,我們將其重新排序成 Z 字型,並再次按照一行行的順序重新回傳字串。
也就是將這一字串重組。
Read More »LeetCode: 6-ZigZag Conversion 解題紀錄LeetCode: 4-Median of Two Sorted Arrays 解題紀錄
題目
Given two sorted arrays nums1 and nums2 of size m and n respectively, return the median of the two sorted arrays.
Follow up: The overall run time complexity should be O(log (m+n)).
Read More »LeetCode: 4-Median of Two Sorted Arrays 解題紀錄LeetCode: 3-Longest Substring Without Repeating Characters 解題紀錄
題目
Given a string s, find the length of the longest substring without repeating characters.
Read More »LeetCode: 3-Longest Substring Without Repeating Characters 解題紀錄LeetCode: 2-Add Two Numbers 解題紀錄
題目
You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.
You may assume the two numbers do not contain any leading zero, except the number 0 itself.
Read More »LeetCode: 2-Add Two Numbers 解題紀錄LeetCode: 1-Two Sum 解題紀錄
題目
Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume that each input would have exactly one solution, and you may not use the same element twice. You can return the answer in any order.Read More »LeetCode: 1-Two Sum 解題紀錄
[C++] STL 中的 map 筆記
map 是 C++ 標準模板函式庫(Standard Template Library, STL)中的關聯容器(Associative Container),也就是存在著 key-value 這樣對應關係的一種容器。
Read More »[C++] STL 中的 map 筆記[C++] STL 中的 deque 筆記
deque 是 C++ 標準模板函式庫(Standard Template Library, STL)中的雙向佇列容器(Double-ended Queue),跟 vector 相似,不過在 vector 中若是要添加新元素至開端,其時間複雜度為 O(N),但在 deque 中則是 O(1)。同樣地,也能在我們需要儲存更多元素的時候自動擴展空間,讓我們不必煩惱佇列長度的問題。
Read More »[C++] STL 中的 deque 筆記