HackerRank Test

hackerrank.txt

Implement a method find that given two lists will find the starting index (indexing is zero based) where the second list occurs as a sub-list in the first list. Your implementation should return -1 if the sub-list cannot be found. Arguments are always defined, non-empty lists.


Sample Input 1

list1 = (1, 2, 3)
list2 = (2, 3)

Sample Output 1
1

Explanation

As second list (2, 3) is sub-list in first list (1, 2, 3) at index 1
 

Sample Input 2

list1 = (1, 2, 3)
list2 = (3, 2)

Sample Output 2
-1

Explanation

As second list is not there in the first list so the output is -1


function LinkedListNode(node_value) {
    this.val = node_value;
    this.next = null;
}

function _insert_node_into_singlylinkedlist(head, val) {
    if(head == null) {
        head = new LinkedListNode(val);
    }
    else {
        var end = head;
        while (end.next != null) {
            end = end.next;
        }
        var node = new LinkedListNode(val);
        end.next = node;
    }
    return head;
}


/*
 * Complete the function below.
 */
/*
For your reference:
LinkedListNode {
    var val;
    var next;
};
*/
function find(l, s) {
    function toList(o) {
        var result = [];
        function getVal(item) {
            result.push(item.val);
            if (item.next) {
                getVal(item.next);
            }
        }
        getVal(o);
        return result;
    }
    
    var list = toList(l);
    var sublist = toList(s);
    var indexStart = list.indexOf(sublist[0]);
    if (indexStart < 0) {
        return -1;
    }
 
  for (var j = 0; j < sublist.length; j++) {

    if (list[indexStart + j] !== sublist[j]) {
       return -1;
    }
  }
  return indexStart;
}

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Let's define a function "LookAndSay" as follow: read off the digits of the input, counting the number of digits in groups of same digit. Here are some examples of this function

LookAndSay(1) = 11                        because 1 is read off as "one 1" or 11. 
LookAndSay(11) = 21                      because 11 is read off as "two 1s" or 21. 
LookAndSay(21) =  1211               because 21 is read off as "one 2, then one 1" or 1211.
LookAndSay(1211) =  111221      because 1211 is read off as "one 1, then one 2, then two 1s" or 111221.
LookAndSay(111221) =  312211 because 111221 is read off as "three 1s, then two 2s, then one 1" or 312211.
 

We then define a "Look and Say" sequence as repeatedly called the "Look and Say" function on its output.

Given a  number start and a number of iteration n, calculate the nth number in a "Look and Say" sequence starting with start.

 

Reusing the previous example with start = 11 and n = 2, LookAndSay(11, 2) = 1211 because LookAndSay(LookAndSay(11)) = 1211

function LookAndSay(start, n) {


}

----


"You have to complete the function convert that takes an integer as its argument and returns the encoded string in base 7 using the following encoding rule:
        
    base 10 0 1 2 3 4 5 6
    base 7 0 a t l s i n

Constraints

    0 <= input <= 1012

Sample Input 1
    
    7

Sample Output 1

    a0

Sample Input 2

    7792875

Sample Output 2

    atlassian

function convert(in) {


}


---------


We have a robot that can pick up blocks from a stash, move them horizontally, and lower them in place. There are 10 positions available to lower blocks, numbered from 0 to 9. Each position can hold up to 15 blocks.
 

The robot understands the commands 'P', 'M' and 'L':

P: Pickup from the stash and move to position 0
M: Move to the next position
L: Lower the block

The robot is safe to operate and very forgiving:


- There are always blocks in the stash (Pickup will always get a block).
- If the robot already holds a block, Pickup will reset the robot to position 0.
- The robot will not go beyond position 9. Trying to Move it further does nothing.
- Lowering a block on a pile of 15 blocks does nothing (and the robot will keep any block it holds).
- Lowering without a block does nothing.
- The robot ignores any command that is not 'P', 'M' or 'L'.
 

Implement a function that takes a String of commands for the robot. The function should output a String representing the number of blocks (in hexadecimal) at each position after running all the commands.

Sample Input 1

String = "PMLPMMMLPMLPMML"

Sample Output 1

"0211000000"

Sample Input 2

"PLPLPLPLPLPLPLPLPLPL"

Sample Output 2

"A000000000"

function compute(instructions) {


}

-------


A third-party provider uses a custom data format to exchange information with us. We need to validate the input before we process it further.

The character encoding is US-ASCII. Valid characters are all the characters between 0x20 (space) and 0x7E (~).

All fields are delimited by '|', and '~' is the escape character. There are only three valid escape sequences:


    '~|' stands for '|'
    '~~' stands for '~'
    '~n' stands for new line


A line represents one record, it must start and end with '|'.

The first line contains the field names. The remaining lines contain the records. Names can't be empty and must be unique, there is no restriction on values.

If a record has more fields than there are names defined, the last name defined will be used and '_#' will be appended to the field name where # is the number of extra record starting at 1.

Here is a valid example:

|name|address|~n|Patrick|[email protected]|[email protected]|~n|Annie||[email protected]|~n

This represents the following data:

name       address             address_1
Patrick    [email protected]    [email protected]
Annie                          [email protected]
        
Valid input should output statistics about the data: number of records, number of fields, number of empty values and the name of the last field. For the previous example, the following output is expected: "2:3:1:address_1"

Invalid input (such as '~~~') should output the following message "0:0:0:format_error"

You have to write a validate function which verifies the input string conforms to the requirements and generates either the expected output or the error message.

function validate(input) {

}