The best run of the season

Problem

"One game on its own tells you nothing; it's the run that counts," the radio commentator likes to say. He has the goal difference of every game of the season, in order: 2 if his team won by two, -1 if it lost by one, 0 for a draw. He wants the stretch of back-to-back games that added up the most.

Write a function that takes that list of whole numbers (never empty) and returns, as a whole number, the largest sum of a stretch of consecutive games. A stretch has at least one game and can go from a single game to the whole season, but you cannot skip games in the middle.

With [2, -3, 4, -1, 2, -5, 3], the best stretch is 4, -1, 2: you return 5. If every game is negative, the best stretch is the least bad game: with [-4, -2, -7] you return -2, not 0.

Examples

• The example

  [2, -3, 4, -1, 2, -5, 3] → 5

• Nothing but wins

  [1, 2, 3] → 6

• Worth crossing the losses

  [3, -1, -1, 4] → 5

• A single game

  [7] → 7

Besides these, the challenge has hidden tests that are revealed when you submit your solution.

You start with this

def best_run(games):
    pass

function bestRun(games) {
}