Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target.
Each number in candidates may only be used once in the combination.
Note:
target) will be positive integers.Example 1:
1 | Input: candidates = [10,1,2,7,6,1,5], target = 8, |
Example 2:
1 | Input: candidates = [2,5,2,1,2], target = 5, |
Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target.
The same repeated number may be chosen from candidates unlimited number of times.
Note:
target) will be positive integers.Example 1:
1 | Input: candidates = [2,3,6,7], target = 7, |
Example 2:
1 | Input: candidates = [2,3,5], target = 8, |
Write a program to solve a Sudoku puzzle by filling the empty cells.
A sudoku solution must satisfy all of the following rules:
1-9 must occur exactly once in each row.1-9 must occur exactly once in each column.1-9 must occur exactly once in each of the 9 3x3 sub-boxes of the grid.Empty cells are indicated by the character '.'.
A sudoku puzzle…
…and its solution numbers marked in red.
Note:
1-9 and the character '.'.9x9.Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.
Example:
1 | Input: [-2,1,-3,4,-1,2,1,-5,4], |
Follow up:
If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.
Given an array of integers nums 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 1:
1 | Input: nums = [5,7,7,8,8,10], target = 8 |
Example 2:
1 | Input: nums = [5,7,7,8,8,10], target = 6 |
Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring.
Example 1:
1 | Input: "(()" |
Example 2:
1 | Input: ")()())" |
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.
Your algorithm’s runtime complexity must be in the order of O(log n).
Example 1:
1 | Input: nums = [4,5,6,7,0,1,2], target = 0 |
Example 2:
1 | Input: nums = [4,5,6,7,0,1,2], target = 3 |
Given an integer n, generate all structurally unique BST’s (binary search trees) that store values 1 … n.
Example:
1 | Input: 3 |