Revision 455abc2b-d152-4df4-8b7e-e1f184516bd0 - Code Golf Stack Exchange

# APL+WIN, <s>35</s> 33 bytes

Two bytes saved thanks to Tbw

Prompts for string of digits:

 ↑(¯1+⍴s)+((s←,⎕)⍷n)/⍳⍴n←⊃,/⍕¨⍳1E3

[Try it online! Thanks to Dyalog Classic][TIO-lpwwhlnl]

[APL (Dyalog Classic)]: https://www.dyalog.com/
[TIO-lpwwhlnl]: https://tio.run/##SyzI0U2pTMzJT9dNzkksLs5M/v@ob6qvz6O2CcZcQJanP5BlyPWooz3t/6O2iRqH1htqP@rdUqypraFRDJTSAarRfNS7PU9T/1HvZqBMHlDwUVezDpA79dAKoJihq/F/oHau/2lc6obqXEASTJiamZiam5hamJiCuYZGxiamZuYWloYGhoaGRobGEKWGQIqLCwA "APL (Dyalog Classic) – Try It Online"