Python greedy algorithms

Take the best-looking choice at each step and never go back: sorting first usually makes the best choice obvious.

It works only when a local best choice can't spoil the whole answer; for meetings, choosing the one that ends earliest leaves the most room.

meetings = [(1, 4), (3, 5), (0, 6), (5, 7)]
end, count = -1, 0
for s, e in sorted(meetings, key=lambda m: m[1]):
    if s >= end:
        count += 1
        end = e
print(count)

Watch for: Sorting by the wrong thing (start instead of end) gives a plausible but wrong answer: try a small case by hand.