Projecteuler added

Author: coderxiang

ProjectEuler/p2.py

@@ -0,0 +1,8 @@
+import sys
+s , x, x1, x2= [0, 0, 1, 0];
+while x <= 4000000:
+	x = x1 + x2;
+	if x <= 4000000 and x % 2 == 0:
+		s += x;
+	x2 = x1; x1 = x; 
+print (s);

ProjectEuler/p3.py

@@ -0,0 +1,30 @@
+import sys;
+
+pm = [];
+st = [True]*1000001;
+
+pm.append (2);
+for i in xrange (4, 1000001, 2):
+	st[i] = False;
+for i in xrange (3, 1000001, 2):
+	if st[i] == True:
+		pm.append (i);
+		for j in range (long(i * i), 1000001L, i):
+			st[j] = False;
+
+while True:
+	n = input ();
+	ans = 2;
+	for x in pm:
+		while n % x == 0:
+			n /= x;
+			ans = x;
+	if n != 1:
+		ans = n;
+	print ans;
+	
+
+	
+
+
+	

ProjectEuler/p4.py

@@ -0,0 +1,11 @@
+ans = -1;
+for i in range (999, 99, -1):
+	for j in range (999, 99, -1):
+		t = i * j;
+		s = str(t);
+		if s == s[::-1] and t > ans:
+			ans = t;
+print (ans);
+
+	
+

ProjectEuler/p48.py

@@ -0,0 +1,5 @@
+md = 10000000000;
+ans = 0;
+for i in range (1, 1001):
+	ans += i ** i;
+print (ans % md);

ProjectEuler/p5.py

@@ -0,0 +1,13 @@
+def gcd (x, y):
+	r = x % y;
+	while r != 0:
+		x = y;
+		y = r;
+		r = x % y;
+	return y
+
+ans = 1;
+for i in range (2, 21):
+	ans = i * ans / gcd (i, ans);
+	
+print (ans);

ProjectEuler/p6.py

@@ -0,0 +1,5 @@
+a = 0; b = 0;
+for i in range (101):
+	a += i**2;
+	b += i;
+print (b**2 - a);