Merge branch 'master' into modernize-python2-code

Project Euler/Problem 01/sol3.py

@@ -13,8 +13,8 @@ try:
 except NameError:
     raw_input = input  # Python 3
 n = int(raw_input().strip())
-sum=0;
-num=0;
+sum=0
+num=0
 while(1):
     num+=3
     if(num>=n):
@@ -44,4 +44,5 @@ while(1):
     if(num>=n):
         break
     sum+=num
+
 print(sum);

Project Euler/Problem 02/sol1.py

@@ -14,7 +14,9 @@ except NameError:
     raw_input = input  # Python 3
 
 n = int(raw_input().strip())
-i=1; j=2; sum=0
+i=1
+j=2 
+sum=0
 while(j<=n):
     if((j&1)==0): #can also use (j%2==0)
         sum+=j

Project Euler/Problem 03/sol1.py

@@ -18,7 +18,7 @@ def isprime(no):
             return False
     return True
 
-max=0
+maxNumber = 0
 n=int(input())
 if(isprime(n)):
     print(n)
@@ -32,8 +32,8 @@ else:
         for i in range(3,n1,2):
             if(n%i==0):
                 if(isprime(n/i)):
-                    max=n/i
+                    maxNumber = n/i
                     break
                 elif(isprime(i)):
-                    max=i
-        print(max)
+                    maxNumber = i
+        print(maxNumber)

Project Euler/Problem 04/sol1.py

@@ -4,13 +4,26 @@ A palindromic number reads the same both ways. The largest palindrome made from
 Find the largest palindrome made from the product of two 3-digit numbers which is less than N.
 '''
 from __future__ import print_function
-n=int(input())
-for i in range(n-1,10000,-1):
-    temp=str(i)
-    if(temp==temp[::-1]):
-        j=999
-        while(j!=99):
-            if((i%j==0) and (len(str(i/j))==3)):
-                print(i)
+limit = int(input("limit? "))
+
+# fetchs the next number
+for number in range(limit-1,10000,-1):
+
+    # converts number into string.
+    strNumber = str(number)
+
+    # checks whether 'strNumber' is a palindrome.
+    if(strNumber == strNumber[::-1]):
+
+        divisor = 999
+
+        # if 'number' is a product of two 3-digit numbers
+        # then number is the answer otherwise fetch next number.
+        while(divisor != 99): 
+            
+            if((number % divisor == 0) and (len(str(number / divisor)) == 3)):
+
+                print(number)
                 exit(0)
-            j-=1
+
+            divisor -=1

Project Euler/Problem 07/sol2.py

@@ -0,0 +1,16 @@
+# By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the Nth prime number?
+def isprime(number):
+	for i in range(2,int(number**0.5)+1):
+		if number%i==0:
+			return False
+	return True
+n = int(input('Enter The N\'th Prime Number You Want To Get: ')) # Ask For The N'th Prime Number Wanted
+primes = []
+num = 2
+while len(primes) < n:
+	if isprime(num):
+		primes.append(num)
+		num += 1
+	else:
+		num += 1
+print(primes[len(primes) - 1])

Project Euler/Problem 16/sol1.py

@@ -0,0 +1,15 @@
+power = int(input("Enter the power of 2: "))
+num = 2**power
+
+string_num = str(num)
+
+list_num = list(string_num)
+
+sum_of_num = 0
+
+print("2 ^",power,"=",num)
+
+for i in list_num:
+    sum_of_num += int(i)
+
+print("Sum of the digits are:",sum_of_num)

Project Euler/Problem 20/sol1.py

@@ -0,0 +1,27 @@
+# Finding the factorial.
+def factorial(n):
+    fact = 1
+    for i in range(1,n+1):
+        fact *= i
+    return fact
+
+# Spliting the digits and adding it.
+def split_and_add(number):
+    sum_of_digits = 0
+    while(number>0):
+        last_digit = number % 10
+        sum_of_digits += last_digit
+        number = int(number/10) # Removing the last_digit from the given number.
+    return sum_of_digits
+
+# Taking the user input.
+number = int(input("Enter the Number: "))
+
+# Assigning the factorial from the factorial function.
+factorial = factorial(number)
+
+# Spliting and adding the factorial into answer.
+answer = split_and_add(factorial)
+
+# Printing the answer.
+print(answer)

Project Euler/Problem 29/solution.py

@@ -0,0 +1,34 @@
+def main():
+    """ 
+    Consider all integer combinations of ab for 2 <= a <= 5 and 2 <= b <= 5:
+
+    22=4, 23=8, 24=16, 25=32
+    32=9, 33=27, 34=81, 35=243
+    42=16, 43=64, 44=256, 45=1024
+    52=25, 53=125, 54=625, 55=3125
+    If they are then placed in numerical order, with any repeats removed, we get the following sequence of 15 distinct terms:
+
+    4, 8, 9, 16, 25, 27, 32, 64, 81, 125, 243, 256, 625, 1024, 3125
+
+    How many distinct terms are in the sequence generated by ab for 2 <= a <= 100 and 2 <= b <= 100?
+    """
+
+    collectPowers = set()
+
+    currentPow = 0
+
+    N = 101     # maximum limit
+
+    for a in range(2,N):
+
+        for b in range (2,N):
+
+            currentPow = a**b   # calculates the current power
+            collectPowers.add(currentPow)   # adds the result to the set
+            
+
+    print "Number of terms ", len(collectPowers)
+
+
+if __name__ == '__main__':
+    main()

Project Euler/README.md

@@ -49,3 +49,10 @@ PROBLEMS:
     Using the rule above and starting with 13, we generate the following sequence:
     13 → 40 → 20 → 10 → 5 → 16 → 8 → 4 → 2 → 1
     Which starting number, under one million, produces the longest chain?
+
+16. 2^15 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.
+    What is the sum of the digits of the number 2^1000?
+20. n! means n × (n − 1) × ... × 3 × 2 × 1
+    For example, 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800,
+    and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.
+    Find the sum of the digits in the number 100!