Авторські розв'язки задач 4 туру

******************** Задача t4z3 ********************

def solve(a):
    
    l = len(a)
    s = sum(a)
    
    for i in range(l - 1):
        si = s - 2 * a[i]
        for j in range(i + 1, l):
            if 2 * a[j] == si:
                return a[i], a[j]

    return 0, 0

n = input()
x = [int(i) for i in raw_input().split()][:n]

r = solve(x)
print r[0], r[1]

******************** Задача t4z4 ********************

a = raw_input()
b = raw_input()

s = []

def solve(i, j):

    if j == len(b):
        return []

    if len(s) > 0 and s[-1] == b[j]:
        t = s.pop()
        r = solve(i, j + 1)
        if r <> None:
            return ["o"] + r
        s.append(t)

    if i < len(a):
        s.append(a[i])
        r = solve(i + 1, j)
        if r <> None:
            return ["i"] + r
        s.pop()

    return None

r = solve(0, 0)

if r <> None:

    for i in r:
        print i,
    print

else:
    print "x"