CareerCup

How many subsets of a given array sum to zero?

Given numbers 1 through 52, take 5 unique numbers and determine
if the number 42 can be made using any combination of addition (+),
subtraction (-), multiplication (*), and division (/) on those 5 numbers

/* Intersection of two sorted interval lists, A=[(1,2), (5,7)..]
B=[(2,6)...] return [(5,6)..] */

import java.util.*;
class Interval{
    int start;
    int end;
    public Interval(int start, int end){
        this.start = start;
        this.end = end;
    }
}
class Solution {
    
    public List<Interval> Intersection(Interval[] i1, Interval[] i2) {}

* Given a string on length N. You can swap only the adjacent elements
and each element can be swapped atmost once.
Find the no of permutations of the string that can be generated after
performing the swaps as mentioned.
Ex –
string – “12345”
Ans = 8
Explanations- (All the permutations)
12345
21345
13245
12435
12354
21435
13254
21354

Given an array of n positive integers, find the number of subarrays
such that product of the elements of those subarrays are less than k.
For eg. Arr= {2, 3, 6} k=10
No of such subarrays= 4

Print the levels of a binary tree in reverse order using stack and recursion

Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root).

For example:
Given binary tree
    3
   / \
  9  20
    /  \
   15   7
return its bottom-up level order traversal as:
[
  [15,7],
  [9,20],
  [3]
]

public List<List<Integer>> levelOrderBottom(TreeNode root) {
}

given an array, find whether there exists 3 elements a,b,c in it such that a+b=c using efficient method.

You are provided a BST, which is corrupted. One of the nodes in it has 2 parents.
Let’s say those are parent 1 and parent 2. It is ensured that none
of these parents will be the ancestor of the other. Identify the node,
and remove the link of the wrong parent.

Given an adjacency matrix of a directed graph, find the number of cycles in the graph

Given an array of n * m matrix, and a moving matrix window (size k * k), move the window from top left to bottom right at each iteration, find the median number inside the window at each moving
Can you do it better than brutal force method?
void getMedian(int[][] matrix,  int k){
	print median
}
For matrix
[
  [1, 5, 3],
  [3, 2, 1],
  [4, 1, 9],
]
The moving window size k = 2. 
 
At first the window is at the start of the array like this
[
  [|1, 5|, 3],
  [|3, 2|, 1],
  [4, 1, 9],
]
,get the median (2 + 3) / 2 = 2.5;
then the window move one step forward.
[
  [1, |5, 3|],
  [3, |2, 1|],
  [4, 1, 9],
]
,get the median (2 + 3) / 2 = 2.5
then the window move one step forward again.
[
  [1, 5, 3],
  [|3, 2|, 1],
  [|4, 1|, 9],
]
,get the median (2 + 3) / 2 = 2.5
then the window move one step forward again.
[
  [1, 5, 3],
  [3, |2, 1|],
  [4, |1, 9|],
]
,get the median (1 + 2) / 2 = 1.5

We are planning an orienteering game.
The aim of this game is to arrive at the goal (G) from the start (S) with the shortest distance.
However, the players have to pass all the checkpoints (@) on the map.
An orienteering map is to be given in the following format.
########
#@....G#
##.##@##
#..@..S#
#@.....#
########
In this problem, an orienteering map is to be given.
Calculate the minimum distance from the start to the goal with passing all the checkpoints.
Specification
* A map consists of 5 characters as following.
You can assume that the map does not contain any invalid characters and
the map has exactly one start symbol 'S' and exactly one goal symbol 'G'.
* 'S' means the orienteering start.
* 'G' means the orienteering goal.
* '@' means an orienteering checkpoint.
* '.' means an opened-block that players can pass.
* '#' means a closed-block that players cannot pass.
* It is allowed to move only by one step vertically or horizontally (up, down, left, or right) to the
next block.
Other types of movements, such as moving diagonally (left up, right up, left down and right down)
and skipping one or more blocks, are NOT permitted.
* You MUST NOT get out of the map.
* Distance is to be defined as the number of movements to the different blocks.
* You CAN pass opened-blocks, checkpoints, the start, and the goal more than once if necessary.
* You can assume that parameters satisfy following conditions.
* 1 <= width <= 100
* 1 <= height <= 100
* The maximum number of checkpoints is 18.

convert prefix to postfix expression
public String convert2postfix(String prefix){

}

Given an array of integers where each element points to the index of the next element how would you detect if there is a cycle in this array

can you do it without extra space

There is a maze of size m*n. You are sitting at (0,0). Another person is sitting in another cell. There are some cheeses placed in different cells with a cell value of 2. Some cells are blocked with a value of 1, thus you cannot pass it, while some cells are filled with 0, thus you can pass it.
You can move to left, right, up, down at each step. You have to collect all the pieces of cheese and then reach to Another Person cell. You need to return the minimum no. of steps required to do so.
Public int getShortest(int[][] maze, int[] anotherPersonCell){
}

In Docker, building an image has dependencies. An image can only be built once
its dependency is built (If the dependency is from outside, then the image can
be built immediately).

Sometimes, engineers make mistakes by forming a cycle dependency of local images.
In this case, ignore the cycle and all the images depending on this cycle.

Input is vector of pair of images (image, its dependency).

Output the order of images to be built in order.

##Example:
```
Example 1:
{{"master", "ubuntu"}, {"numpy", "master"}, {"tensorflow", "numpy"}}
Output: master, numpy, tensorflow

Example 2:
{{"python", "numpy"}, {"numpy", "python"}, {"tensorflow", "ubuntu"}}
Output: tensorflow

Example 3:
{{"b", "c"}, {"c", "d"}, {"a", "b"}, {"d", "e"}, {"e","c"}, {"f", "g"}}
Ouput: f

There are n servers, reboot time is S0, S1..Sn-1
There are m tasks, the completion of the time required are T0, T1… Tm-1
How to assign tasks to each server makes the total time the shortest

Given a binary tree, how do you serialize and deserialize. Remember it is not BST it is a general binary tree which can also have duplicate elements.

Find the largest repeating sub-string in a string.
ex: banana
ans is: ana

Input: expression_tree | sequence_of_operations

The input is a single line of text with a expression tree and a sequence of operations separated by | character and ended by a \n newline character. Spaces are allowed in the input but should be ignored.

The expression tree is a sequence of 1-character variables A-Z and with sub expression trees formed by parenthesis (expression_tree). Examples: AB, A(B C D), (AB)C((DE)F)

The sequence of operations is a string of with characters R (reverse) or S (simplify)

Reverse means reverse the order of everything in expression tree. Applying reverse twice in a row cancels out. Example: (AB)C((DE)F) | R should print (F(ED))C(BA)

Simplify means remove the parentheses around the very first element in the expression tree and each of its subexpression trees. Applying S multiple times should have same result as applying S once. Example: (AB)C((DE)F) | S should print ABC(DEF)
String process(String input){

}

..

Convert Json string to Map

public Map jsonToMap(String t) {

}

Design Distributed Web Crawler.

What if server is slow, how to solve
What if one server is down

Array has N integers，range[0...N-1]。Set S[k], 0 <= K < N as S[K] = {A[K], A[A[K]], A[A[A[K]]],....},
write a function returns the size of the largest set S[K] for this array. return 0 if empty.
ex:
A = [5, 4, 0, 3, 1, 6, 2]
return 4 because S[2] equals {0, 5, 6, 2} 4 elements

Given an array of integers and a target number, determine if an arithmetic expression using these integers can be evaluated to the target number, you are allowed to use '+', '-', '*', '/'. Follow-up: when evaluating the expression, take operand precedence into account,
public boolean getTarget(int[] nums, int target){
}


exponentia is ok

find the Closest leaf to a given node in Binary Tree
can you do it in o(n) time
public TreeNode findCloestLeafNode(TreeNode root, TreeNode target){}

no parent pointer

validate IP in string format and return the uint32 format

‘1.2.3.4’ -> 0x01020304

Given a n-nery tree and its deep copy, a node in the original tree, return the corresponding node in the copy
public TreeNode getCopyNode(TreeNode root, TreeNode copy, TreeNode node)

Write the code to find the median of an unsorted array in average linear time.
followup the array is distributed across many machines.

Write a function to split a SQL query into individual statements.
give you a String which contains a separate Query with a semicolon ";" return all valid queries
Such as
"select name from courseinfo ;; select * from db1 where home = 'usa' ;"
The main thing to consider is that some special cases such as the escape symbol and the quotation marks inside the semicolon
public List<String> getQuery(String queries){
}