Project Euler – Problem # 11 – Solved with Python

Problem 11 solved with help from: Help with creating a list of lists

Problem:

What is the greatest product of four numbers on the same straight line in the 20 by 20 grid?

20 x 20 (20×20.txt) file in the same directory as problem_11.py

f = open('20x20.txt', 'rU')
x = []
max_prod = 0

for m in xrange(20):                # Create a list of lists with x
    x.append([])
    for n in xrange(20):
        x[m].append(int(f.read(3)))
                          
f.close()

        # Check horizontally for max_prod...
        
for i in range(len(x)):                 
    for j in range(len(x[i])-3):       
        horiz = (x[i][j])*(x[i][j+1])*(x[i][j+2])*(x[i][j+3])
        if horiz > max_prod:
            max_prod = horiz

        # Check vertically for max_prod...
    
for i in range(len(x[i])-3):        
    for j in range(len(x)):
        vert = (x[i][j])*(x[i+1][j])*(x[i+2][j])*(x[i+3][j])
        if vert > max_prod:
            max_prod = vert

        # Check diagonally right for max_prod...
       
for i in range(len(x[i])-3):        
    for j in range(len(x[i])-3):
        diag_right = (x[i][j])*(x[i+1][j+1])*(x[i+2][j+2])*(x[i+3][j+3])
        if diag_right > max_prod:
            max_prod = diag_right

        # Check diagonally left for max_prod...
            
for i in range(3,len(x)):           
    for j in range(len(x[i])-3):
        diag_left = (x[i][j])*(x[i-1][j+1])*(x[i-2][j+2])*(x[i-3][j+3])
        if diag_left > max_prod:
            max_prod = diag_left

print "Max product = %s" % max_prod

Project Euler

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Project Euler Problem # 8 – Solved with Java & Python!

Find the greatest product of five consecutive digits in the 1000-digit number.

73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450

One Possible Solution: Java

import java.io.*;

public class Problem_08 
	{
		  public static void main( String [] args )
		  {
		    try
		    {
		       FileReader fro = new FileReader( "1000.txt" );
		       BufferedReader bro = new BufferedReader( fro );
		       StringBuilder sb = new StringBuilder( );
		  
		       // declare String variable and prime the read
		       String stringfromFile = bro.readLine( );
		 
		       while( stringfromFile != null ) // end of the file
		       {
		          sb.append(stringfromFile); // append into one long string
		          stringfromFile = bro.readLine( );  // read next line
		       }
		       String str = sb.toString( ); // convert from StringBuilder to String
		       String fiveDigits = ""; // initialize fiveDigits
		       int largest = 0; // initialize largest
		       
		       for(int i = 0; i < str.length() - 4; i++){
		    	    fiveDigits = str.substring( i, ( i + 5 )); // substring of str for fiveDigits
		    	    
		    	    // convert each of the five digits into integers
		    	    int v = Integer.parseInt(fiveDigits.substring(0, 1));
		    	    int w = Integer.parseInt(fiveDigits.substring(1, 2));
		    	    int x = Integer.parseInt(fiveDigits.substring(2, 3));
		    	    int y = Integer.parseInt(fiveDigits.substring(3, 4));
		    	    int z = Integer.parseInt(fiveDigits.substring(4, 5));
		    	    
		    	    // find the product of each of the five digits
		    	    int product = v * w * x * y * z;
		    	    
		    	    // keep track of the largest product
		    	    if(product > largest)
		    	    {
		    	    	largest = product;
		    	    }
		       }
		       System.out.println("Largest = " + largest);
		       bro.close( );
		    }
		 
		    catch( FileNotFoundException filenotfoundexxption )
		    {
		      System.out.println( "1000.txt, does not exist" );
		    }
		 
		    catch( IOException ioexception )
		    {
		      ioexception.printStackTrace( );
		    }
		  }
	}

One Possible Solution: Python

# Python version = 2.7.2
# Platform = win32

fjf = open('1000.txt', 'rU')
bcm = fjf.readlines()
hws = ''.join(bcm)
bvc = hws.replace('\n', '')
fjf.close()

largest = 0

for i in range(0, (len(bvc) - 4)):
    fiveDigits = bvc[i:(i + 5)]

    x1 = int(fiveDigits[0:1])
    x2 = int(fiveDigits[1:2])
    x3 = int(fiveDigits[2:3])
    x4 = int(fiveDigits[3:4])
    x5 = int(fiveDigits[4:5])
    
    product = x1 * x2 * x3 * x4 * x5
    
    if product > largest:
        largest = product
        
print "Greatest product is: %s" % largest

Euler Project

Bald Eagle along the Poudre River Trail

Bald Eagle along the Poudre River Trail
Today and yesterday, along the Poudre River Trail, I spotted at least three bald eagles. They seem to hang out in one particular area near the bridge. It’s really neat to see them take off and fly, showing off their large wingspan.