Equilibrium index: Difference between revisions

=={{header|Wren}}==

<lang ecmascript>var equilibrium = Fn.new { |a|

var len = a.count

var equi = []

if (len == 0) return equi // sequence has no indices at all

var rsum = a.reduce { |acc, x| acc + x }

var lsum = 0

for (i in 0...len) {

rsum = rsum - a[i]

if (rsum == lsum) equi.add(i)

lsum = lsum + a[i]

}

return equi

}

var rset = Fn.new { |m, n|

var s = "%(n)"

var c = s.count

return (m > c) ? " " * (m - c) + s : s

}

var tests = [

[-7, 1, 5, 2, -4, 3, 0],

[2, 4, 6],

[2, 9, 2],

[1, -1, 1, -1, 1, -1, 1],

[1],

[]

]

System.print("The equilibrium indices for the following sequences are:\n")

for (test in tests) {

System.print("%(rset.call(24, test)) -> %(equilibrium.call(test))")

}</lang>

{{out}}

<pre>

The equilibrium indices for the following sequences are:

[-7, 1, 5, 2, -4, 3, 0] -> [3, 6]

[2, 4, 6] -> []

[2, 9, 2] -> [1]

[1, -1, 1, -1, 1, -1, 1] -> [0, 1, 2, 3, 4, 5, 6]

[1] -> [0]

[] -> []

</pre>