Thursday, February 19, 2015

How to run npm installed components from commandline in Windows?

When you are working with windows and nodejs, then you might face this problem, whatever npn packages you install might not be accessible through commandline. By this I mean, is that, suppose you did:

npm install -g bower

And then executed :

bower install

Windows might give you an error that 'bower' is unrecognized.
A solution to the problem is to add npm global repository to your system path. To do so execute

npm config get prefix

To get the npm global repository path. Copy this path and follow following steps to add to windows path:

  1. On your computer, select Start->Settings->Control Panel->System:
  2. A "System Properties" dialog box will appear. Click it's Advanced tab:
  3. Click the Environment variables button:
  4. An Environment Variables dialog box will appear. In the System variables section, scroll down until you find the PATH variable. Select this variable:
  5. Click the Edit button to edit the value of this variable.
  6. At the end of the "Variable value:" box, add
            ;
    
  7. Click the OK button in each dialog box, until they have all disappeared.

Once, added you would have to restart command prompt and Hola! everythings works :)

Wednesday, February 11, 2015

AI Planning Tree Search Algorithm for Missionary And Cannibal Problem in Java

I have been doing AI Planning course and I decided to implement the first basic problem in Java. To implement this, i tried to create the algorithm with right level of abstractions so that it can be applied to any problem in future.

Some take aways in my package structure is that, I have maintained all the generic reusable code in definitions package and problem specific code in monkcannibal package.

To solve the problem, I have implemented State which had successor method, IProblem which defined the problem to solve and IStrategy which defined the strategy to take for state transition. Here I have used two strategies for tree travesal, breadth first search aka, BFS and Depth First Search, aka DFS.

The code is available on github at: https://github.com/biplav/aiplanning

The main file is : com.biplav.aiplanning.problems.monkcanibbal.MissionaryCannibalPlan.java


And the output is:

1:L->3m1cfalseboat R->0m2ctrueboat
2:L->3m2ctrueboat R->0m1cfalseboat
3:L->3m0cfalseboat R->0m3ctrueboat
4:L->3m1ctrueboat R->0m2cfalseboat
5:L->1m1cfalseboat R->2m2ctrueboat
6:L->2m2ctrueboat R->1m1cfalseboat
7:L->0m2cfalseboat R->3m1ctrueboat
8:L->0m3ctrueboat R->3m0cfalseboat
9:L->0m1cfalseboat R->3m2ctrueboat
10:L->1m1ctrueboat R->2m2cfalseboat
11:L->0m0cfalseboat R->3m3ctrueboat
Time consumed is 3
1:L->2m2cfalseboat R->1m1ctrueboat
2:L->3m2ctrueboat R->0m1cfalseboat
3:L->3m0cfalseboat R->0m3ctrueboat
4:L->3m1ctrueboat R->0m2cfalseboat
5:L->1m1cfalseboat R->2m2ctrueboat
6:L->2m2ctrueboat R->1m1cfalseboat
7:L->0m2cfalseboat R->3m1ctrueboat
8:L->0m3ctrueboat R->3m0cfalseboat
9:L->0m1cfalseboat R->3m2ctrueboat
10:L->0m2ctrueboat R->3m1cfalseboat
11:L->0m0cfalseboat R->3m3ctrueboat

Time consumed is 1

Zopper Programming assignment Question 3 (Project Group)

The third question is also a simple one:

Link to the question is on HackerRank: http://www.hackerearth.com/problem/algorithm/project-team/

The submission code in python can be seen here:

Zopper Programming Assessment Problem 2 with solution

This is the second problem from HackerEarth that I tried for the friend for interview:

Problem:
HackerMan says that 5 and 8 are smart digits. A positive integer is called a smart number if it has only smart digits in its decimal representation.
HackerMan has three sets of numbers. And he needs your help to find out the number of distinct smart numbers that he can make using one number from each of the three sets. You have to help in it
Note: You must not count the same smart number more than once.
Constraints
  • The three sets will contain between 1 and 50 elements, inclusive.
  • Each number in the three sets will contain numbers between 1 and 30,000, inclusive.
Input Format
  • The first, third and fifth lines will contain a number N that will specify the count of numbers in the sets on the second, fourth and sixth lines of input.
  • The second, fourth and sixth line will contain the three sets of numbers respectively.
Output Format
Print a single line containing the count of distinct smart numbers.

Sample Input 
3
3 5 4
3
2 1 3
3
2 1 5
Sample Output
2
Explanation
We have two smart numbers 5 = 3 + 1 + 1 and 8 = 5 + 2 + 1. 8 can be also expressed as 4 + 2 + 2, but you must not count 8 twice.

Time Limit: 2 sec(s) for each input file.
Memory Limit: 256 MB
Source Limit: 1024 KB
Marking Scheme: Marks are awarded if any testcase passes.
Allowed languages: C, C++, Clojure, Go, Haskell, C#, Java, JavaScript, Objective-C, Perl, PHP, Python, Ruby

SUBMISSIONS

Solution: https://gist.github.com/biplav/69f8c0c305b378be2b35

if __name__ == "__main__":
        n = raw_input()
        list1 = raw_input()
        n=raw_input()
        list2 = raw_input()
        n=raw_input()
        list3 = raw_input()
        list1 = [int(n) for n in list1.split(" ")]
        list2 = [int(n) for n in list2.split(" ")]
        list3 = [int(n) for n in list3.split(" ")]
        bigList = []
        for n in list1:
                for m in list2:
                        for o in list3:
                                bigList.append(n+m+o)
        bigList = list(set(bigList))
        #print bigList
        #bigList.sort()
        smart_number = 0
        for n in bigList:
                smart_number = smart_number+1 if (n % 10 == 5 or n % 10 == 8) else smart_number
        print smart_number

Tuesday, February 10, 2015

Zopper online assesment question on HackerEarth with solution.

Recently a friend asked me to solve a problem which he got on one of the interview, online assessment test. I decided to document my solution here. The companies name was Zopper and the question was asked on the initial online screening test on HackerEarth.

Problem:

HackerMan says that 5 and 8 are smart digits. A positive integer is called a smart number if it has only smart digits in its decimal representation.
HackerMan has three sets of numbers. And he needs your help to find out the number of distinct smart numbers that he can make using one number from each of the three sets. You have to help in it
Note: You must not count the same smart number more than once.
Constraints
  • The three sets will contain between 1 and 50 elements, inclusive.
  • Each number in the three sets will contain numbers between 1 and 30,000, inclusive.
Input Format
  • The first, third and fifth lines will contain a number N that will specify the count of numbers in the sets on the second, fourth and sixth lines of input.
  • The second, fourth and sixth line will contain the three sets of numbers respectively.
Output Format
Print a single line containing the count of distinct smart numbers.

Sample Input 
3
3 5 4
3
2 1 3
3
2 1 5
Sample Output 
2
Explanation
We have two smart numbers 5 = 3 + 1 + 1 and 8 = 5 + 2 + 1. 8 can be also expressed as 4 + 2 + 2, but you must not count 8 twice.

Time Limit: 2 sec(s) for each input file.
Memory Limit: 256 MB
Source Limit: 1024 KB
Marking Scheme: Marks are awarded if any testcase passes.
Allowed languages: C, C++, Clojure, Go, Haskell, C#, Java, JavaScript, Objective-C, Perl, PHP, Python, Ruby




MAX_ROW=500
MAX_COL=500


def assign_walls(row,col):
        w = raw_input()
        inp = w.split(" ")
        if inp[0] is 'C':
                col.append(int(inp[1]))
        else:
                row.append(int(inp[1]))

def main():
        sections = []
        row = []
        col = []
        section_areas=[]
        row_counter = 0
        col_counter = 0
        row_section = [(0,MAX_ROW)]
        col_section = [(0,MAX_COL)]
        no_of_walls = raw_input()
        for i in range(int(no_of_walls)):
                assign_walls(row,col)
        row.sort()
        col.sort()
        #print row
        #print col
        for i in row:
                if(i < row_section[row_counter][1]):
                        row_end = row_section[row_counter][1]
                        row_start = row_section[row_counter][0]
                        row_section[row_counter] = (row_start,i)
                        row_section.append((i,row_end))
                        row_counter = row_counter+1
        for i in col:
                if(i < col_section[col_counter][1]):
                        col_end = col_section[col_counter][1]
                        col_start = col_section[col_counter][0]
                        col_section[col_counter] = (col_start,i)
                        col_section.append((i,col_end))
                        col_counter = col_counter+1
        #print row_section
        #print col_section
        for i in row_section:
                row_length = i[1]-i[0]
                #print row_length
                for j in col_section:
                        col_length = j[1]-j[0]
                        #print col_length
                        area = row_length*col_length
                        #print area
                        section_areas.append(area)
        return section_areas[len(section_areas)-1]


if __name__ == "__main__":
        out = []
        t = raw_input()
        for i in range(int(t)):
                out.append(main())
        for x in out: