def validbrackets(s):
    openers = "({[<"
    closers = ")}]>"
    counts = [0,0,0,0]
    oldopeners = []
    for i in range(len(s)):
        for j in range(len(openers)):
            if s[i] == openers[j]:
                counts[j] += 1
                oldopeners.append(j)
            elif s[i] == closers[j]:
                if len(oldopeners) == 0 or j != oldopeners.pop():
                    return 0
                counts[j] -= 1
        for j in counts:
            if j < 0:
                return 0
    for cnt in counts:
        if cnt != 0:
            return 0
    return 1

print validbrackets("<{[()]([[[]]])}>")
print validbrackets("<{[(]([[[]]])}>")
print validbrackets("<{[(]([[[]]])}>)")
print validbrackets("<hello (world)[]>")

1
0
0
1