problem4533.py

import itertools,operator

ops=[operator.add,operator.sub,operator.mul,operator.div]
opCombs = list(itertools.product(ops,ops,ops))

def customReduce(operators,nums):
    total = nums[0]
    for i in range(len(operators)):
        if operators[i] == operator.div and nums[i+1]==0:
            return 1000001
        if operators[i] == operator.div and total%nums[i+1]!=0:
            return 1000001
        total = operators[i](total,nums[i+1])
    return total 
    #operators[0](operators[1](operators[2](nums[0],nums[1]),nums[2]),nums[3])
    
    
f=open("4533.txt","r")
lines = [map(int,a.strip().split(" ")) for a in f if a.strip()!="0 0 0 0"]
print lines

for a in lines:
    results = set()
    perms = list(itertools.permutations(a,4))
    for b in perms:
        for c in opCombs:
            results.add(customReduce(c,b))
    d = sorted(list(results))
    print d
    longestChain=0
    currentChain=0
    longestChainLastItem = 1000001
    lastItem = 1000001
    for b in d:
        if b == lastItem+1:
            currentChain+=1
        else:
            if currentChain>longestChain:
                longestChain = currentChain
                longestChainLastItem = lastItem
                currentChain=0
            else:
                currentChain=0
        lastItem = b
    print longestChainLastItem,longestChain