Solutions to http://adventofcode.com/2016/day/3

d3p1.py

#!/usr/bin/env python3

# functional solution to http://adventofcode.com/2016/day/3 part 1
# Mark Jenkins <mark@markjenkins.ca>

from sys import stdin

def possible_triangle(args):
    assert(len(args)==3)
    sum_args = sum(args)
    return all(
        (sum_args - n) > n
        for n in args )

print( sum( 1  
            for line in stdin
            if possible_triangle(tuple(int(s) for s in line.split()) )
            ) # sum
       ) # print

d3p2.py

#!/usr/bin/env python3

# solution to http://adventofcode.com/2016/day/3 part 2 which illustrates
# the use of zip() to perform column iteration
# Mark Jenkins <mark@markjenkins.ca>

def possible_triangle(args):
    assert(len(args)==3)
    sum_args = sum(args)
    return all(
        (sum_args - n) > n
        for n in args )

def stdin_lines_until_eof():
    try:
        while True:
            yield input()
    except EOFError: pass

def next_n(iteration, n):
    result_tuple = tuple( next(iteration)
                          for i in range(n) )
    if len(result_tuple) != n:
        raise StopIteration()
    else:
        return result_tuple

def n_at_a_time(iteration, n):
    while True:
        result = next_n(iteration, n)
        yield result

def parsed_three_at_a_time_triangles_stdin():
    return n_at_a_time( ( tuple(int(p) for p in line.split())
                          for line in stdin_lines_until_eof()), 3)

print( sum( 1
            for three_tri in parsed_three_at_a_time_triangles_stdin()
            for tri in zip(*three_tri)
            if possible_triangle(tri) ) )