A steady beat

Problem

Nora recorded a drum rehearsal without a metronome and wrote down the millisecond when each hit landed. Now she wants to know if she kept perfect time: every hit the same distance from the next.

Write a function that takes hits, a list of integers from smallest to largest with no repeats (it may be empty), and returns true if the gap between each hit and the next is always the same, and false if not. No one gives you that gap: the reference is the gap between the first two hits, and every other gap is compared with it.

With [0, 250, 500, 750] it returns true. With [100, 400, 700, 950] it returns false: the gaps are 300, 300 and 250. With two hits or fewer there is nothing to compare, so it returns true.

Examples

• Steady

  [0, 250, 500, 750] → true

• Rushes at the end

  [100, 400, 700, 950] → false

• One out of place in the middle

  [0, 50, 110, 150, 200] → false

• Two hits

  [1000, 1500] → true

• Five steady hits

  [7, 19, 31, 43, 55] → true

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

You start with this

def steady_beat(hits):
    pass

function steadyBeat(hits) {
}