viveksyngh

__author__ = 'Vivek'
#This function returns all the factors of an integer in sorted order
def allFactors(A):
    """
    :param: A positive integer
    :return: All the factors of the integer in sorted order.
    """
    res = []
    firstHalf = []
    secondHalf = []

viveksyngh

__author__ = 'Vivek'

def isPrime(A):
    """
    :param: An integer
    :return: Returns integer True if it's prime otherwise false

    """
    if A == 1:
        return False

viveksyngh

__author__ = 'Vivek'
#Implementation of Sieve of eratosthenes , It returns an array containing all prime numbers less than A ( Including A)
def sieve(A):
    """
    :param: An integer A
    :return: An array of prime number less than equal to A
    """
    L = [1] * (A + 1)
    L[0] = 0
    L[1] = 0

viveksyngh

#Given a positive integer which fits in a 32 bit signed integer, 
#Find if it can be expressed as A^P where P > 1 and A > 0. A and P both should be integers.
def isPower(A):
      """
      Returns True if number can be expressed as A^P where  P > 1 and A > 0
      :param: A an integer
      :return: True if it can be expressed as A^P otherwise False
      """
        if A == 1 :
            return True

viveksyngh

def arrange(self, A):
        for i in range(len(A)) :
            A[i] += (A[A[i]]%len(A)) * len(A)
        for i in range(len(A)) :
            A[i] = A[i]/len(A)
            
# Rearrange a given array so that Arr[i] becomes Arr[Arr[i]] with O(1) extra space.
# Input: arr[]  = {3, 2, 0, 1}
# Output: arr[] = {1, 0, 3, 2}

viveksyngh

#A robot is located at the top-left corner(Start) of an A x B grid 
#The robot can only move either down or right at any point in time. 
#The robot is trying to reach the bottom-right(Finish) corner of the grid 
#How many possible unique paths are there ?
def nCr(self, n, r) :
        f = math.factorial
        return f(n)/f(r)/f(n -r)
        
    def uniquePaths(self, A, B):
        return self.nCr(A+B-2, B -1)

viveksyngh

#Given an even number ( greater than 2 ), return two prime numbers whose sum will be equal to given number.
def primesum(n):
        for i in xrange(2, n):
            if is_prime(i) and is_prime(n - i):
                return i, n - i

def is_prime(n):
    if n < 2:
      return False

viveksyngh

def titleToNumber(self, A):
        alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        num = 0
        for i in range(len(A)) :
            num += (alphabet.index(A[i]) + 1) *  (26 ** (len(A) - i - 1) )
        return num
#A -> 1
#B -> 2
#C -> 3 

viveksyngh

def convertToTitle(A):
        aplhabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        column = ""
        while A > 0 :
            temp = A%26
            #print temp, A
            if temp == 0 :
                temp = 26
                A = A - 1
            #print aplhabet[temp-1]

viveksyngh

#Determine whether an integer is a palindrome. Do this without extra space.
#A palindrome integer is an integer x for which reverse(x) = x where reverse(x) is x with its digit reversed.
#Negative numbers are not palindromic.
def isPalindrome(self, A):
        num = 0
        if A < 0 :
            return False
        temp = A
        while temp != 0 :
            num = num*10 + (temp%10)