LeetCode 42. Trapping Rain Water
Description:
Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.
LeetCode 41. First Missing Positive
LeetCode 41. First Missing Positive
Description:
Given an unsorted integer array, find the first missing positive integer.
Your algorithm should run in O(n) time and uses constant space.
LeetCode 39. Combination Sum
LeetCode 39. Combination Sum
Description:
Given a set of candidate numbers (C) (without duplicates) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.
The same repeated number may be chosen from C unlimited number of times.
Note:
All numbers (including target) will be positive integers.
The solution set must not contain duplicate combinations.
LeetCode 34. Search for a Range
LeetCode 34. Search for a Range
Description:
Given an array of integers sorted in ascending order, find the starting and ending position of a given target value.
Your algorithm’s runtime complexity must be in the order of O(log n).
If the target is not found in the array, return [-1, -1].
Example:
Given [5, 7, 7, 8, 8, 10] and target value 8,
return [3, 4].
LeetCode 33. Search in Rotated Sorted Array
LeetCode 33. Search in Rotated Sorted Array
Description:
Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).
You are given a target value to search. If found in the array return its index, otherwise return -1.
You may assume no duplicate exists in the array.
LeetCode 31.NextPermutation
LeetCode 31.NextPermutation
Description:
Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.
If such arrangement is not possible, it must rearrange it as the lowest possible order (ie, sorted in ascending order).
The replacement must be in-place, do not allocate extra memory.
LeetCode 18. 4Sum
LeetCode 18. 4Sum
Description:
Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target.
Note: The solution set must not contain duplicate quadruplets.
LeetCode 16. 3Sum Closest
LeetCode 16. 3Sum Closest
Description:
Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution.
LeetCode 15. 3Sum
LeetCode 15. 3Sum
Description:
Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.
Note: The solution set must not contain duplicate triplets.