Upto Problem10

prob1.py

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+# Project Euler
+# Problem - 1 
+# Add all the natural numbers below one thousand that are multiples of 3 or 5.
+
+s = 0
+i = 3
+
+while i < 1000 :
+    if (i%3 == 0 or i%5 == 0) :
+        s = s + i
+    i = i + 1
+print "%d" % s

prob10.py

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+# Project Euler
+# Problem - 8
+# Calculate the sum of all the primes below two million.
+
+from math import sqrt
+
+s = 2
+
+def is_prime(n) :
+    for j in range(2, int(sqrt(n)) + 1) :
+        if (n % j == 0) :
+            return 0
+    return 1
+
+for i in range(3, 2000000) :
+    if is_prime(i) :
+        s = s + i
+print s

prob2.py

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+# Project Euler
+# Problem - 2
+# By considering the terms in the Fibonacci sequence whose values do not exceed
+# four million, find the sum of the even-valued terms.
+
+# Each new term in the Fibonacci sequence is generated by adding the previous two terms.
+# The first two terms of fibonacci sequence will be 1 and 2.
+
+a = 1
+b = 2
+c = a + b
+s = b
+
+while c < 4000000 :
+    if (c % 2 == 0) :
+        s = s + c
+    a = b
+    b = c
+    c = a + b
+print s

prob3.py

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+# Project Euler
+# Problem - 3
+# Find the largest prime factor of a composite number.
+
+c = int(raw_input("Enter any Composite number : "))
+i = 2
+j = 1
+cnt = 0
+
+while i < c :
+    if  c % i == 0 :
+        x = c / i
+        while j < x :
+            if x % j == 0 :
+                cnt = cnt + 1
+            j = j + 1
+        j = 1
+        if (cnt == 1) :
+            lpf = x
+            break
+        cnt = 0
+    i = i + 1
+print lpf

prob4.py

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+# Project Euler
+# Problem - 4
+# Find the largest palindrome made from the product of two 3-digit numbers.
+
+p = 0
+
+for a in range(100, 1000) :
+    for b in range(100, a) :
+        c = a * b
+        if c > p :
+            s = str(a * b)
+            if s == s[::-1] :
+                p = a * b
+print p

prob5.py

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+# Project Euler
+# Problem - 5
+# What is the smallest positive number that is evenly divisible by all of
+# the numbers from 1 to 20?
+
+i = 20
+cnt = 0
+while i > 0 :
+    for j in range(1, 21) :
+        if ( i % j == 0 ) :
+            cnt = cnt + 1
+    if (cnt == 20) :
+        break
+    cnt = 0
+    i = i + 1
+print i

prob6.py

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+# Project Euler
+# Problem - 6
+# What is the difference between the sum of the squares and the square of the sums?
+
+from math import pow
+
+n = int(raw_input("Enter n : "))
+
+sum_of_squares = n * (n + 1) * (2 * n + 1) / 6
+square_of_sums = pow(n, 2) * pow(n + 1, 2) / 4
+
+print "\nThe difference between the sum of the squares and the square of the sums of first %d natural numbers is : %d" % (n, square_of_sums - sum_of_squares)

prob7.py

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+# Project Euler
+# Problem - 6
+# What is the 10001st prime number?
+
+from math import sqrt
+
+count = 0
+num = 2
+
+def is_prime(n) :
+    cnt = 0
+    for i in range(1, int(sqrt(n)) + 1) :
+        if (n % i == 0) :
+            cnt = cnt + 1
+    if (cnt == 1) :
+        return 1
+    else :
+        return 0
+
+while(1) :
+    if is_prime(num) :
+        count = count + 1
+    if count >= 10001 :
+        break
+    num = num + 1
+
+print num

prob8.py

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+# Project Euler
+# Problem - 8
+"""
+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
+
+"""
+
+num = '73167176531330624919225119674426574742355349194934\
+96983520312774506326239578318016984801869478851843\
+85861560789112949495459501737958331952853208805511\
+12540698747158523863050715693290963295227443043557\
+66896648950445244523161731856403098711121722383113\
+62229893423380308135336276614282806444486645238749\
+30358907296290491560440772390713810515859307960866\
+70172427121883998797908792274921901699720888093776\
+65727333001053367881220235421809751254540594752243\
+52584907711670556013604839586446706324415722155397\
+53697817977846174064955149290862569321978468622482\
+83972241375657056057490261407972968652414535100474\
+82166370484403199890008895243450658541227588666881\
+16427171479924442928230863465674813919123162824586\
+17866458359124566529476545682848912883142607690042\
+24219022671055626321111109370544217506941658960408\
+07198403850962455444362981230987879927244284909188\
+84580156166097919133875499200524063689912560717606\
+05886116467109405077541002256983155200055935729725\
+71636269561882670428252483600823257530420752963450'
+
+start = 0
+end = 5
+prod = 0
+x = 1
+
+while (end <= 1000) :
+    for i in range(start, end) :
+        x = x * int(num[i])
+    if (prod < x) :
+        prod = x
+    x = 1
+    start += 1
+    end += 1
+print prod

prob9.py

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+# Project Euler
+# Problem - 8
+"""
+    Find the only Pythagorean triplet, {a, b, c}, for which a + b + c = 1000.
+
+    A Pythagorean triplet is a set of three natural numbers, a < b < c, for which,
+a^2 + b^2 = c^2
+
+For example, 3^2 + 4^2 = 9 + 16 = 25 = 5^2.
+
+There exists exactly one Pythagorean triplet for which a + b + c = 1000.
+Find the product abc.
+
+"""
+
+for a in range(1, 1000) :
+    for b in range((a + 1), 1000) :
+        c = 1000 - a - b
+        if ( c*c == a*a + b*b) :
+            print a*b*c
+            exit