CareerCup

Given a function rand32() (random number range 0-2**32-1) that randomly generates a 32-bit int, design a new random function:
Randn(n) generates a random distributed random number (0 - 2**n-1)
Rand3n(n) generates (0 - 3**n-1) the uniformly distributed random number

Topic: There is a set of coordinates. The original format of each coordinate is (1.3, 0.5). However, the comma and decimal point are gone. Only one string is left, allowing you to restore all possible combinations. For example, 123, possible (1, 23) (1, 2.3) (12, 3) (1.2, 3)

given period and threshold, Assume there is a endless streaming events, each event occurs at timestamp "x". The question want you to write an API that return true if number of the events are over the threshold within the period around timestamp "x"


Ex:
period = 3, threshold =2
getEvent(10) -> false
getEvent(12) -> false
getEvent(13) -> true [10,12,13]
getEvent(20) -> false


part one: event come in order
part two: event come without order

Given vector<int> nums, and pair<int, int> range. Find out how many continuous subsequences within this vector sum up the number within the range.

Input: [1, 2, 3], [3,6]
Output: (4)

because [1,2,3], [1,2], [2,3], [3]

Each have a (x,y) coordinate.
Write an API that group three Googler together for lunch if they are close enough. Otherwise, throw them in un-schedule pool.

Distance formula = sqrt((x1-x2) ^2 + (y1-y2) ^2)
Given an int range;

Range: 2
Input | Output of API Un-schedule pool
0,0 -> [] [[0,0]]
1,0 -> [] [[0,0], [1,0]]
3,0 -> [] [[0,0], [1,0], [3,0]]
1,1-> [[0,0], [1,0], [1,1]] [[3,0]]

Given an vector<int> nums and an int target, you can change any element of the vector to positive or negative. How many uniquely different vector sum up to target?
Input: [1,1,1], target = 2
[-1,1,1]
[1,-1,1]
[1,1,-1]

return (3)

find max path sum in DAG, weight can be negative

Implement a method to check if a n-ary tree is unival

class TreeNode {
int val;
List<TreeNode> children;
TreeNode(int val) {
this.val = val;
children = new ArrayList<>();
}
}

Given the length and width of a rectangle, how many ways can be used to go from the upper left corner to the upper right corner (each step can only go to the right, top right or bottom right):
-follow up 1: If three points in the rectangle must be visited, how many ways
-follow up 2: If you are given an point H, and the path must go down below the H point, how to do it

The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "root." Besides the root, each house has one and only one parent house. After a tour, the smart thief realized that "all houses in this place forms an n-nary tree". It will automatically contact the police if two directly-linked houses were broken into on the same night.
Determine the maximum amount of money the thief can rob tonight without alerting the police.
/**
* Definition for a n-ary tree node.
* public class TreeNode {
* int val;
* List<TreeNode> kids;
* }
*/
class Solution {
public int rob(TreeNode root) {

}
}

For two string a, b, their distance is defined as the number of positions at which the corresponding character are different.
Now you can swap characters at any two locations once, and ask how to swap to make the distance the smallest.

preorder Traversing a n-ary tree without using recurrsion

TreeNode<T> {
T val;
List<TreeNode> children;
}

Given two methods for the person class, one to find a dad and one to find a mother, using these two methods to achieve a method to determine whether the two people are related to blood, assuming a limited number of people.

Self-implemented data structures and methods, output all the heirs. To achieve birth (parent, name), dead (name), getAllSucession (). There is a king, you can use birth plus children, dead dead. The order of inheritance is the same as preorder except that this tree has multiple children.

Given an Input file of IPv4 addresses, filter and write them into Valid and Invalid IPs.

Input file = ["192.100.0.1, "10.0.0.1", "aa.bb.cc.dd", "10.0", "999.10.10.1"]
Valid = []
Invalid = []

A coffee machine has three buttons (S, M, L). After pressing each button, the coffee machine will flow out of a range of coffee [s1, s2], [m1, m2], [l1, l2], but the outflow of coffee The amount is random. There is a cup with a total capacity of c2. There is a tick c1 on the cup. If the amount of coffee is [c1, c2], it is considered full.
After asking for a series of button operations, can the coffee be filled in [c1, c2] but not overflow?

Input like method stack trace: "main, start", "foo, start", foo, end", "bar, start", "bar end", "main, end", "main2, start", "main2, end"
Output String, such as the following format, to indicate the order in which the method was called and the hierarchy

main
       Foo
       Bar
main2

public TreeNode{
int val = val;
TreeNode left, right;
public TreeNode(int val){
this.val = val;
}
given a tree and an API, delete a part of the nodes in the tree and return the forest formed after the node is deleted.
public List<TreeNode> deletenodes(TreeNode root, List<TreeNode> toDeletes){

}
example

1
 / \
 2  3
/  / \
4  5 6
If you delete the 2 and 5 nodes, you will need to return to the forest
[4,     1]
         \
          3
           \
           6

turns the following format string into a tree: node has keys, values, and subtrees.


For example, the first key is node1 and the value is ‘aaaa’


<node1>aaaaa<node2>bbbbb</node2><node3>cccc</node3><node4>dddd</node4></node1>

find longest common suffix of two linked list.

Give a 0/1 matrix to find and remove the islands. Assume that the boundaries of the matrix are 1
The definition of islands is surrounded by 0

The simplest example is
enter:
111111
100001
100101
100001
111111

Output:
111111
100001
100001
100001
111111

Write a hash function so that a string and its reverse get the same return value

Hash(‘banana’) == hash(‘ananab’)
Hash(‘banana’) == hash(‘banana’)
Hash(‘banana’) != hash(‘banaaa’)

x={a,b,c}, y={p,q}, z={r,s}
Define a
Operation, x * y * z = {{a,p,r},{a,p,s},{a,q,r},{a,q,s}......{c,q s}}
Is to output all the results in the order of each subset, implementing a class iterator that has Next() and hasNext() methods

Give a tree-like graph that lets you find the maximum length from the leaf node to the leaf node. The input is an array of edges.

Last Man Standing
A king gathers all the men in the kingdom who are to be put to death for their crimes, but because of his mercy, he will pardon one. He gathers the men into a circle and gives the sword to one man. The man kills the man to his left, and gives the sword to the man to the dead man's left. The last man alive is pardoned.

With 5 men, the 3rd is the last man alive.

Write a program that accepts a single parameter: a number N that represents the number of criminals to start with. The program should output the number of the last two men alive.

Example #1: myProgram 5

would output:

5, 3

Example #2: myProgram 7

would output:

3, 7

To determine whether two people have kinship, all data structures need their own definition

Given an integer n (say somewhere between 100 and 1000), you want to generate a random binary tree having exactly n nodes. You are only interested in the structure of the tree. Each structurally unique tree should ideally have the same chance of being generated.

Given a binary matrix, find if there is a path from the upper left corner to the lower right corner, meet the conditions each time the value of the cell must be different.
Follow up if there is a path with the same number of 0 and 1?

Given k numbers as strings. The numbers may be very large (may not fit in long long int), the task is to find sum of these k numbers.
Example
S1 = “100”
S2 = “10”
S3 = “1”
Return “111”
public string addNumbers(String[] nums){
}

There is a process sequence that contains the start and end of each process. There is a query sequence asking how many processes are running at a certain point in time. Please return the query result of the query sequence.


Example
Given logs = [[1, 1234], [2, 1234]], queries = [2], return [2].

Explanation:
There are 2 processes running at time 2.
Given logs = [[1, 1234], [2, 1234]], queries = [1, 1235], return [1, 0].

Explanation:
There is a process running at time 1, and 0 processes running at time 1235.