Given an unsorted integer array, find the first missing positive integer.
For example, Given
[1,2,0]
return3
, and[3,4,-1,1]
return2
.Your algorithm should run in O(n) time and uses constant space.
leetcode 全排列详解
本文为leetcode 全排列的详解,包括:
- 31 Next Permutation
- 46 Permutations
- 47 Permutations II
- 60 Permutation Sequence
leetcode 55 Jump Game || 45 Jump Game II
leetcode 38 Count and Say
The count-and-say sequence is the sequence of integers beginning as follows:
1, 11, 21, 1211, 111221, ...
1
is read off as"one 1"
or11
.11
is read off as"two 1s"
or21
.21
is read off as"one 2
, thenone 1"
or1211
.Given an integer n, generate the _n_th sequence.
Note: The sequence of integers will be represented as a string.
leetcode 36. Valid Sudoku || 37. Sudoku Solver
leetcode 32 Longest Valid Parentheses
Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring.
Example 1:
Input: "(()" Output: 2 Explanation: The longest valid parentheses substring is "()"
Example 2:
Input: ")()())" Output: 4 Explanation: The longest valid parentheses substring is "()()"
leetcode 30 Substring with Concatenation of All Words
You are given a string, S, and a list of words, L, that are all of the same length. Find all starting indices of substring(s) in S that is a concatenation of each word in L exactly once and without any intervening characters.
For example, given: S:
"barfoothefoobarman"
L:["foo", "bar"]
You should return the indices:
[0,9]
. (order does not matter).
leetcode 29 Divide Two Integers
Divide two integers without using multiplication, division and mod operator.
If it is overflow, return MAX_INT.
leetcode 11 Container With Most Water
Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.
Note: You may not slant the container.