kflu

class PrintParenth:
    def __init__(self, n):
        self.n = n
        self.s = [None for i in range(2*n)]

    def P(self, l, r):
        if l==self.n and r==self.n:
            yield ''.join(self.s)
        if l < self.n:
            self.s[l+r] = '('

kflu

def strperm(S):
    if not S: yield ""
    for c in S:
        for perm in strperm(S - set([c])):
            yield c + perm

for s in strperm(set("abcd")):
    print s

kflu

def C(S,k):
    '''Choose k elements from set S.'''
    assert len(S) >= k
    if k==0:
        yield set()
    S1 = S.copy()
    for s in S:
        S1.remove(s)
        if len(S1) >= k-1:
            for c in C(S1, k-1):

kflu

using System;
using System.Collections.Generic;

namespace ConsoleApplication14
{
    class Program
    {
        static void Main(string[] args)
        {
            var A = new int[] { 4, 3, 5, 2 };

kflu

class QSort:
    def __init__(self, A):
        self.A = A
    def partition(self, L, U):
        s = U
        p = L
        while s != p:
            if self.A[p] <= self.A[s]:
                p += 1
            else:

kflu

using System;
using System.Diagnostics;
using System.Collections.Generic;

namespace ConsoleApplication4
{
    /// <summary>
    /// 
    /// </summary>
    /// <remarks>

kflu

using System.Text;
using System;
using System.Diagnostics;

namespace ConsoleApplication15
{
    class Program
    {
        static void Main(string[] args)
        {

kflu

using System;
using System.Collections.Generic;
using System.Diagnostics;

namespace ConsoleApplication7
{
    class Program
    {
        static void Main(string[] args)
        {

kflu

// Deprecated in favor of https://github.com/puzzl3r/puzzles/tree/master/CheckTreeBalance

using System.Diagnostics;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication8
{

kflu

from Queue import Queue

def find_path(E, V, n1, n2):
    """Find path between n1,n2 of a directed graph"""
    for n in E:
        n.from_ = None
    q = Queue()
    q.put(n1)
    found = False
    while not q.empty():