import random

def find_max(list):
    max = list[0] # first entry
    for cur in list[1:]: # from 2nd entry on
        if max < cur:
            max = cur
    return max

# finds max using tournament strategy
def find_max2(list):
    # variable descriptions:
    #    pairings: list of indexes of competitors in current round;
    #      consecutive pairs of these compete in the round.
    #    winners: list of indexes of winners in current round
    pairings = range(0,len(list))
    num_cmps = len(pairings)/2
    print list
    while num_cmps >= 1:
        winners = []
        winners_vals = []
        print "Round of", num_cmps*2
        for i in range(0,num_cmps):
            idx1 = pairings[2*i]
            idx2 = pairings[2*i+1]
            if list[idx1] > list[idx2]:
                winners.append(idx1)
                winners_vals.append(list[idx1])
            else:
                winners.append(idx2)
                winners_vals.append(list[idx2])
        print "pairings: ", pairings
        print "winners:  ", winners
        print "data:     ", winners_vals
        pairings = winners
        num_cmps = num_cmps/2
    return list[winners[0]]

# finds max and 2nd max using tournament strategy
def find_max_max2(list):
    # variable descriptions:
    #    pairings: list of indexes of competitors in current round;
    #      consecutive pairs of these compete in the round.
    #    winners: list of indexes of winners in current round
    #    losers: a dictionary of indexes of who lost to whom
    pairings = range(0,len(list))
    num_cmps = len(pairings)/2 # how many comparisons for this round
    losers = {}
    for i in range(0,len(list)):
        losers[i] = []
    print list
    while num_cmps >= 1:
        winners = []
        winners_vals = [] # only used for output for debugging
        print "Round of", num_cmps*2
        for i in range(0,num_cmps):
            idx1 = pairings[2*i]
            idx2 = pairings[2*i+1]
            if list[idx1] > list[idx2]:
                winners.append(idx1)
                winners_vals.append(list[idx1])
                losers[idx1].append(idx2)
            else:
                winners.append(idx2)
                winners_vals.append(list[idx2])
                losers[idx2].append(idx1)
        print "pairings: ", pairings
        print "winners:  ", winners
        print "data:     ", winners_vals
        pairings = winners
        num_cmps = num_cmps/2
    # now index of winner is in winners[0]

    # now find 2nd max
    print losers[winners[0]]
    max2list = losers[winners[0]]
    max2idx = max2list[0]
    for idx in max2list[1:]:
        if list[idx] > list[max2idx]:
            max2idx = idx    
    return (list[winners[0]],list[max2idx])

# creates a random list
def random_list(n, min=0, max=9):
    list = [] # empty list
    for i in range(n):
        list.append( random.randint(min, max) )
    return list

def main():
    #data = [ 1, 3, -5, 7, 0, -2, 2, 6 ]
    data = random_list(8)
    print data
    print "max, max2 are: \n", find_max_max2(data)

#for i in range(1,len(data)-1):
#    cur = data[i]
#    for j in range(i-1,0):

main()