Write a function that takes as inputs the integer indices $n$ and iin$\{1,$dots,$N\},$ and returns as its output the sparse elementary vector $e_i.$

To do this, replace each $??$ with appropriate code.

using SparseArrays: sparsevec

function ei$($i::Integer, $n$ ::Integer$)$

@assert $)(n)(1$

ei $,??)$

return ei

end

$$ Revert

X Code errored $(18$ms$)$

LoadError: syntax: invalid identifier name $"?"$

syntax: invalid identifier name $"?"$

Stacktrace:

$[1]$ top$-$level scope at In$[9]$:$5$

$[2]$ include$\_$string$($::Function, ::Module, ::String, ::String$)$ at

$./$loading$.$jl:$1091$