Get me back down to 1 rep!

Question

This is not an invitation for you to downvote everything I've posted. Just sayin' ;)

Challenge

Figure out how I can get myself back down to 1 reputation.

Details will follow input format, then followed by output.

Input

Input will consist of the my current reputation, the number of questions I have posted with an accepted answer (that is not my own), the number of questions I have posted without an accepted answer that have a valid answer that is not my own, and the number of answer downvotes that I have cast.

Details

Accepting an answer that is not my own gives me 2 rep. Unaccepting an answer takes away 2 rep from me. Undownvoting an answer gives me 1 rep (we assume that all of my answer votes are not locked in at the moment), and downvoting an answer makes me lose 1 rep (we assume there are enough answers on PPCG for me to not care about the number of answers that I can downvote). We also ignore potential serial vote reversal. Most of my reputation is going to have to be given away by bounties because I don't want to go around downvoting 5000 answers.

The challenge is to find the shortest way to get me back down to 1 rep using the shortest code. Please keep in mind that I need at least 125 rep to downvote and at least 75 rep to start a bounty. By "shortest way", I mean the way requiring the least actions, where each accept and downvote and their reverse actions and each bounty is a separate action. Note that it is impossible to award a bounty of more than +500 rep at once. Also note that you can only give out bounties in 50 rep increments.

If there is no way to get back down to 1 rep, then output some consistent error message. The error message may be output through crashing.

Output

Output the number of undownvotes, downvotes, accept-votes, unaccept-votes, and bounty actions I need to perform in any consistent order in any reasonable list format.

Test Cases

reputation, accepted_answers, no_accept_questions, answer_downvotes -> accepts, unaccepts, downvotes, undownvotes, bounties

101, 3, 2, 10 -> 0, 0, 0, 0, 1 // This one's easy, just give out a 100 rep bounty.
102, 3, 2, 10 -> 0, 1, 0, 1, 1 // Unaccept to get to 100, then undownvote to get to 101, then give a +100 bounty
103, 3, 2, 10 -> 0, 1, 0, 0, 1 // First unaccept one of those answers and then give out a 100 rep bounty or vice versa
3, 1, 0, 0 -> 0, 1, 0, 0, 0 // Unaccept that answer and lose the 2 rep
1000, 0, 1, 0 -> 1, 0, 1, 0, 2 // Accept an answer to get to 1002, then downvote an answer to get to 1001, then give out two +500 bounties

Rules

• Standard Loopholes Apply
• "Post a bunch of spam and get suspended" is not an answer, nor is anything similar

• In the case of a tie between shortest methods, output one possible shortest method

• This is code-golf, so the shortest code in bytes wins!

Answer 1

Mathematica, 302 bytes

Golfed version:

Unprotect@Null;Null=0;f[1,_,_,_]={,,,,};f[r_,a_,n_,d_]:=(f[r,a,n,d]=l={∞,,,,};f[r,a,n,d]=#&@@MinimalBy[{If[r>74,{,,,,1}+f[r-50Min[⌈r/50⌉-1,10],a,n,d],l],If[r>124,{,,1,,}+f[r-1,a,n,d+1],l],If[d>0,{,,,1,}+f[r+1,a,n,d-1],l],If[a>0,{,1,,,}+f[r-2,a-1,n+1,d],l],If[n>0,{1,,,,}+f[r+2,a+1,n-1,d],l]},Tr])

Normal version:

Unprotect@Null; Null = 0;
f[1, _, _, _] = {, , , ,};
l = {\[Infinity], , , ,};
f[r_, a_, n_, d_] := (
  f[r, a, n, d] = l;
  f[r, a, n, d] = # & @@ MinimalBy[{
      If[r > 74, {, , , , 1} + 
        f[r - 50 Min[\[LeftCeiling]r/50\[RightCeiling] - 1, 10], a, n,
          d], l],
      If[r > 124, {, , 1, ,} + f[r - 1, a, n, d + 1], l],(* 
      downvote one more *)
      If[d > 0, {, , , 1,} + f[r + 1, a, n, d - 1], l],
      (* un-downvote *)
      If[a > 0, {, 1, , ,} + f[r - 2, a - 1, n + 1, d], l],
      (* un-accept. -2 rep *)
      If[n > 0, {1, , , ,} + f[r + 2, a + 1, n - 1, d], l]
      (* accept. +2 rep *)
      }, Tr]
  )

Note:

1. Test this on https://sandbox.open.wolframcloud.com/ - paste the code, press Shift+Enter, then enter f[101,3,2,10] for example for first test case, then press Shift+Enter.
2. Use Block[{Null=0}, ...] can save some bytes, but I haven't test that.
3. Sometimes $IterationLimit=$RecursionLimit=∞ is necessary to get correct result.
4. The function will return {∞,0,0,0,0} or similar (that is, the sum of elements in list is infinite) when it is impossible, and a list with format similar to that in the sample output when it is possible.