Rearrange the digits in ⟨1263045⟩ to meet the rules below.
⟨6th 5th 4th 3rd 2nd 1st 0th⟩
✅Match
{p6, p3, p1, p0} = ? + {0,1,3,4}
Jump(3,6) ≤ 1
2nd → a, 0th → b, ab=5+6n
⟨ ¹ˢᵗ↓ ⟩ after 3×⟨→⟩
⛔Avoid
⟨⋯ 6 ⋯ 2 ⋯ 0 ⋯ 4 ⋯⟩
6th|4th|3rd|2nd → 1
#125034_v2.6
┌───┬───┬───┬───┬───┬───┬───┐
│6th│5th│4th│3rd│2nd│1st│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │ │ │ │ │ │ │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 2 │ │ │ │ │ 5 │ │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 3 │ │ │ 2 │ │ 5 │ │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 4 │ │ 6 │ 2 │ │ 5 │ │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 5 │ │ 6 │ 2 │ │ 5 │ 4 │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 6 │ 0 │ 6 │ 2 │ │ 5 │ 4 │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 7 │ 0 │ 6 │ 2 │ 3 │ 5 │ 4 │ 1 │▒
└───┴───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
Proof of 2024-08-13 Q1(m=6)
═══════════════════════════
Notation: if nth -> a, then we write [nth] = a.
To begin with, observe that ✅「2nd → a, 0th → b, ab=5+6n」 implies
(1) {[2nd], [0th]} = {1,5}.
So, in view of ⛔「6th|4th|3rd|2nd → 1」, we get
┌───┬───┬───┬───┬───┬───┬───┐
│6th│5th│4th│3rd│ 2■│1st│ 0■│▒
╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒
Step 1 │ │ │ │ │ │ │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 2 │ │ │ │ │ 5 │ │ 1 │▒
└───┴───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┬───┐
│ │ 2 │ 6 │ 3 │ 0 │ 4 │ │
└───┴───┴───┴───┴───┴───┴───┘
Let S := {p6, p3, p1, p0}. Given that 1 = [0th] ∈ S and 5 = [2nd] ∉ S, to match ✅「{p6, p3, p1, p0} = ? + {0,1,3,4}」 we need
(2) {p6, p3, p1, p0} = {0,1,3,4}.
┌───┬───┬───┬───┬───┬───┬───┐
│*6 │5th│4th│*3 │2nd│*1 │*0 │
╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡
│ ▬ │ │ │ ▬ │ 5 │ ▬ │ 1 │
└───┴───┴───┴───┴───┴───┴───┘
--- Idle ---
┌───┬───┬───┬───┬───┬───┬───┐
│ │ 2 │ 6 │ │ │ │ │
└───┴───┴───┴───┴───┴───┴───┘
where "▬" are occupied by 0,3,4.
It follows that {[5th], [4th]} = {2,6}. Since we need a "↓" at 1st to match ✅「⟨ ¹ˢᵗ↓ ⟩ after 3×⟨→⟩」, we have [4th] != 6. Consequently, we get
┌───┬───┬───┬───┬───┬───┬───┐
│6th│ 5■│ 4■│3rd│2nd│1st│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒
│ │ │ │ │ 5 │ │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 3 │ │ │ 2 │ │ 5 │ │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 4 │ │ 6 │ 2 │ │ 5 │ │ 1 │▒
└───┴───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┬───┐
│ │ │ │ 3 │ 0 │ 4 │ │
└───┴───┴───┴───┴───┴───┴───┘
We check the value of [1st]. By ✅「⟨ ¹ˢᵗ↓ ⟩ after 3×⟨→⟩」, it is not 0, and by ✅「Jump(3,6) ≤ 1」, it is not 3. So, [1st] = 4:
┌───┬───┬───┬───┬───┬───┬───┐
│6th│5th│4th│3rd│2nd│ 1■│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒
│ │ 6 │ 2 │ │ 5 │ │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 5 │ │ 6 │ 2 │ │ 5 │ 4 │ 1 │▒
└───┴───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┬───┐
│ │ │ │ 3 │ 0 │ │ │
└───┴───┴───┴───┴───┴───┴───┘
Finally, to avoid ⛔「⟨⋯ 6 ⋯ 2 ⋯ 0 ⋯ 4 ⋯⟩」, we finish by
┌───┬───┬───┬───┬───┬───┬───┐
│ 6■│5th│4th│ 3■│2nd│1st│0th│▒
╞═══╪═══╪═══╪═══╪═══╪═══╪═══╡▒
│ │ 6 │ 2 │ │ 5 │ 4 │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 6 │ 0 │ 6 │ 2 │ │ 5 │ 4 │ 1 │▒
├───┼───┼───┼───┼───┼───┼───┤▒
Step 7 │ 0 │ 6 │ 2 │ 3 │ 5 │ 4 │ 1 │▒
└───┴───┴───┴───┴───┴───┴───┘▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
--- Idle ---
┌───┬───┬───┬───┬───┬───┬───┐
│ │ │ │ │ │ │ │
└───┴───┴───┴───┴───┴───┴───┘
Q.E.D.
#125034_v2.6