Puzzle
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Ponder This Challenge - December 2020 - Maximal losing vote

Let's consider a simplified version of the USA elector-based election system. In our system, the states are represented by a vector pop = [p1, p2, ..., pn] of odd numbers, given the number of eligible voters in any state.

Each state is allocated a given number of electors in the following manner: There are 1,001 electors in total, and they are assigned to states in proportion to their population. If p = p1+p2+...+pn, then state i receives (pi/p)*1001 electors, rounded down. The remaining electors are allocated one at a time for the states, ordered by the size of the remaining fractional elector (e.g., a state that got 3.5 electors will get another one before a state with 10.25 electors).

For example, if pop = [51, 61, 77, 89, 99] then the electors are [135, 162, 205, 236, 263].

There are two candidates in the election. If a candidate receives more than half the votes in a state, she gets all the electors for that state. The candidate with the most electors wins the election.

A vote is a vector [v1, v2,..,vn] that represents the number of votes a candidate received in all the states. The size of a vote is v1+v2+...+vn - the total number of votes for that candidate. A losing vote is a vote that results in losing the election (i.e., not getting enough electors). A losing vote is maximal with respect to a given population vector pop if any vote of a larger size is not a losing vote.

Your goal: Find a population vector p=[p1, p2, p3, p4, p5] on five states with 101<=pi<= 149 and a maximal losing vote v=[v1, v2, v3, v4, v5] such that the size of v is 71.781305% the size of p up to a millionth of a percent.

Present your answer in the following format:
[p1, p2, p3, p4, p5]
[v1, v2, v3, v4, v5]

A bonus '*' for computing the maximal losing vote for the 2020 presidental election (where the populations are the eligble voters for each state, but the electors are computed by the non-simplified, real-world formula).

Solution

  • One possible solution is
    P = [101, 101, 115, 125, 125]
    V = [50, 50, 57, 125 125]

    A solution to the bonus question requires some source of USA voter data; there isn't one canonical source, so multiple answers were accepted. One answer by Florian Fischer used http://www.electproject.org/2020g and gave the result 77.92%, which is typical; the answers mostly range between 77-79%.

Solvers

  • Lorenz Reichel (30/11/2020 4:42 PM IDT)
  • Michal Politowski (30/11/2020 5:10 PM IDT)
  • Daniel Chong Jyh Tar (30/11/2020 5:29 PM IDT)
  • Guillaume Escamocher (30/11/2020 8:16 PM IDT)
  • *Dan Dima (30/11/2020 8:16 PM IDT)
  • Bert Dobbelaere (30/11/2020 8:18 PM IDT)
  • Uoti Urpala (30/11/2020 10:39 PM IDT)
  • Eden Saig (1/12/2020 2:31 AM IDT)
  • Colas Kerkhove (1/12/2020 4:22 AM IDT)
  • Xiao Liu (1/12/2020 8:20 AM IDT)
  • *Matt Rips (1/12/2020 8:33 AM IDT)
  • *Bertram Felgenhauer (1/12/2020 8:57 AM IDT)
  • Graham Hemsley (1/12/2020 3:15 PM IDT)
  • Benjamin Lui (1/12/2020 5:14 PM IDT)
  • S Wirth (1/12/2020 6:45 PM IDT)
  • *Jacob Siemons (1/12/2020 11:10 PM IDT)
  • Keith Schneider (2/12/2020 3:53 AM IDT)
  • *Muralidhar Seshadri (1/12/2020 1:12 PM IDT)
  • Sean Egan (2/12/2020 5:24 AM IDT)
  • *Alper Halbutogullari (1/12/2020 1:25 PM IDT)
  • *andy greig (2/12/2020 2:24 PM IDT)
  • James Dow Allen (2/12/2020 2:56 PM IDT)
  • *David Greer (2/12/2020 3:52 PM IDT)
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  • Hu Shuai (2/12/2020 4:26 PM IDT)
  • *Dieter Beckerle (2/12/2020 7:09 PM IDT)
  • Chuck Carroll (2/12/2020 11:26 PM IDT)
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  • Yasodhar Patnaik (4/12/2020 4:09 AM IDT)
  • Liubing Yu (4/12/2020 9:01 AM IDT)
  • *Vladimir Volevich (4/12/2020 8:42 PM IDT)
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  • Karl D’Souza (4/12/2020 11:58 PM IDT)
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  • *Latchezar Christov (6/12/2020 9:40 AM IDT)
  • *Sanandan Swaminathan (6/12/2020 10:19 AM IDT)
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  • Rob Pratt (6/12/2020 8:07 PM IDT)
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  • *Daniel Moolman (4/12/2020 1:18 PM IDT)
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  • Shouky Dan & Tamir Ganor (8/12/2020 8:26 AM IDT)
  • Ingo Ogertschnig (8/12/2020 11:41 AM IDT)
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  • Alex Fleischer (8/12/2020 3:32 PM IDT)
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  • Ilya Tarygin (9/12/2020 12:02 AM IDT)
  • Tyler Mullen (9/12/2020 1:24 PM IDT)
  • Almog Yair (9/12/2020 10:22 PM IDT)
  • *Eric Manalac (9/12/2020 12:08 PM IDT)
  • *Arthur Vause (10/12/2020 11:22 AM IDT)
  • Sri Mallikarjun J (11/12/2020 1:32 PM IDT)
  • Sebastian Bohm and Martí Bosch (11/12/2020 4:20 PM IDT)
  • Clive Tong (12/12/2020 11:22 AM IDT)
  • Walter Sebastian Gisler (12/12/2020 9:27 PM IDT)
  • *Motty Porat (13/12/2020 12:43 AM IDT)
  • Kamlesh Nahata (13/12/2020 1:53 AM IDT)
  • Aviran Sadon (13/12/2020 6:44 PM IDT)
  • Hansraj Nahata (13/12/2020 7:48 PM IDT)
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  • *Li Li (15/12/2020 5:46 PM IDT)
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  • Emma Barry (17/12/2020 2:48 PM IDT)
  • Daniel Bitin (19/12/2020 8:33 PM IDT)
  • Amir Sarid (20/12/2020 12:43 AM IDT)
  • *Florian Fischer (20/12/2020 3:20 AM IDT)
  • James Muir (20/12/2020 2:10 PM IDT)
  • Mathias Schenker (20/12/2020 5:21 PM IDT)
  • Nyles Heise (21/12/2020 6:50 AM IDT)
  • Chris Shannon (21/12/2020 11:01 AM IDT)
  • Harold Gutch (23/12/2020 7:51 PM IDT)
  • Shirish Chinchalkar (25/12/2020 11:50 PM IDT)
  • Paul Revenant (26/12/2020 9:05 PM IDT)
  • Karl Mahlburg (27/12/2020 3:41 AM IDT)
  • Fabio Michele Negroni (27/12/2020 5:29 PM IDT)
  • Harald Bögeholz (28/12/2020 4:28 AM IDT)
  • Sumanth Ravipati (28/12/2020 8:21 AM IDT)
  • Joaquim Carrapa (30/12/2020 3:55 AM IDT)
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  • Clement Heyd (31/12/2020 12:35 AM IDT)
  • Andreas Stiller (31/12/2020 1:20 AM IDT)
  • Zhou Hangbo (31/12/2020 3:33 PM IDT)
  • Li Wang (31/12/2020 3:33 PM IDT)
  • Radu-Alexandru Todor (1/1/2021 2:14 AM IDT)
  • Kang Jin Cho (2/1/2021 3:06 AM IDT)
  • Oscar Volpatti (2/1/2021 7:17 AM IDT)
  • Kareenahalli, Suryaprasad (3/1/2021 8:24 PM IDT)
  • Vincent Beaud (3/1/2021 9:20 PM IDT)
  • Albert Stadler (3/1/2021 11:49 PM IDT)
  • Fakih Karademir (11/1/2021 12:33 PM IDT)
  • Kirsten Sugar (25/1/2021 7:49 PM IDT)

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