The DNA sequence is composed of a series of nucleotides abbreviated as ‘A’, ‘C’, ‘G’, and ‘T’.
- For example, “ACGAATTCCG” is a DNA sequence.
When studying DNA, it is useful to identify repeated sequences within the DNA.
Given a string s that represents a DNA sequence, return all the 10-letter-long sequences (substrings) that occur more than once in a DNA molecule. You may return the answer in any order.
Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no such substring, return the empty string “”.
The testcases will be generated such that the answer is unique.
A substring is a contiguous sequence of characters within the string.
Given an input string (s) and a pattern (p), implement wildcard pattern matching with support for ‘?’ and ‘*’ where:
- ‘?’ Matches any single character.
- ‘*’ Matches any sequence of characters (including the empty sequence).
The matching should cover the entire input string (not partial).
84. Largest Rectangle in Histogram
Given an array of integers heights representing the histogram’s bar height where the width of each bar is 1, return the area of the largest rectangle in the histogram.
Given an unsorted integer array nums, return the smallest missing positive integer.
You must implement an algorithm that runs in O(n) time and uses constant extra space.
Given two integers n and k, return all possible combinations of k numbers out of the range [1, n].
You may return the answer in any order.
Given an array of distinct integers nums and a target integer target, return the number of possible combinations that add up to target.
The test cases are generated so that the answer can fit in a 32-bit integer.
Find all valid combinations of k numbers that sum up to n such that the following conditions are true:
- Only numbers 1 through 9 are used.
- Each number is used at most once.
Return a list of all possible valid combinations. The list must not contain the same combination twice, and the combinations may be returned in any order.
Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target.
Each number in candidates may only be used once in the combination.
Note: The solution set must not contain duplicate combinations.
Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.