In this simple but fun challenge, you were asked to determine if Jimmy would fall of their platform. Jimmy has three body parts /, o, and arranged like this

/o

Platforms are represented with -. Jimmy will fall off their platform iff they have two or more body parts that are not directly above a platform.

Some examples:

 /o
- -------

Jimmy will balance since all their body parts are above a -.

 /o
 ------ ---

Jimmy will balanced since two body parts are above -s.

 /o
-- ---- --

Jimmy will balance even though they are split between two platforms

 /o
 -

Jimmy will not balanced since two body parts are not above a platform.

Your task is to write a program that takes a platform as a lengthed container containing only -s and s (e.g. a string) and outputs the number of Jimmys that can be placed on the platform such that none of them will fall and none of them will overlap. A Jimmy may have one of their body parts to the left of the beginning of the string or the right of the end of the string.

This is code-golf so answers are scored in bytes with fewer bytes being the aim.

Test cases

Inputs

- - -

- -
--
-- --
----
- -- --
------- -

Respective outputs

0
0
1
1
2
2
2
3

JavaScript (ES6),  45 41  40 bytes

Saved 4 bytes thanks to @Shaggy

s=>(0+s+0).split(/.--|-.-|--./).length-1

Try it online!

Python 2, 53 bytes

lambda s:len(re.findall('.--|-.-|--.',`s`))
import re

Try it online!

Based on Arnauld's regex. Greedily searches for all the non-overlapping length-3 substrings with two or more -. A trick is to do `s` to enclose the input string in quotes as padding to leave room for Jimmys to hang off on either end like

/o/o
'----'

Python 2, 57 bytes

f=lambda s:'--'in s[:3]*2and-~f(s[3:])or s>''and f(s[1:])

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Requires a cheesy I/O format of the input already in quotes. Outputs False for 0.

A recursive function that places each Jimmy on the leftmost position allowed, by either placing Jimmy over the first three characters if they can hold Jimmy, or otherwise deleting the first character. A cute trick is to check if s[:3] contains two or more - by doing '--'in s[:3]*2, which concatenates two copies of s[:3] and checks for two adjacent -.

Perl 5 -p, 28 bytes

Uses the same method as @Arnauld's JavaScript.

$_=@a=" $_ "=~/.--|-.-|--./g

Try it online!

Japt, 16 bytes

Based on Arnauld's original JS solution. I tried a few different methods to get the necessary padding either side of the input but all came in at the same length - still searching for a shorter way...

ûUÊÄÄ è".--|-."ê

Test it

ûUÊÄÄ è".--|-."ê :Implicit input of string U
û :Centre pad with spaces to length
 UÊ : Length of U
 ÄÄ : Add 1, twice
 è :Count the occurrences of
 ".--|-."ê : ".--|-." palindromised, resulting in the RegEx /.--|-.-|--./g

Stax, 13 bytes

ƒó±KêyG←à╛Ωô∟

Run and debug it

Excel, 96 bytes

A1 = platform.
Entered as array Formula Ctrl+Shift+Enter

=SUM(IF(LEN(TRIM(MID(IF(MOD(LEN(A1),3)=1," ","")&A1,3*ROW(INDIRECT("A1:A"&LEN(A1)))-2,3)))>1,1))