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Singapore govt dating app uses Gale-Shapley stable marriage algorithm

466 points · 499 comments · rzk

  1. qihqi · · focus · HN ↗
    Depending on the which gender does the initiation; the result is either male optimal (males get the best he can get, females gets the worst among those she would tolerate) or female optimal. I wonder which version this one is.
    1. jb1991 · · focus · HN ↗
      The article also mentioned that, but I don’t understand it. Receivers are also making choices, so why do they end up with the worst match?
      1. 2muchcoffeeman · · focus · HN ↗
        Imagine you are the proposer. You will start at the top of your list and work your way down only if rejected. So you are guaranteed to the best you could possibly do.

        Imagine A ranks X,Y,Z in that order B ranks Y,X,Z in that order C ranks X,Y,Z

        X, Y, Z rank A,B,C in that order.

        A will propose to X and match. B will propose to Y and match. C will propose to X and get rejected. C will propose to Y and get rejected. C will propose to Z and match.

        Y will never get a proposal from A. Z will never get a proposal from A or B.

        Edit: I think I fixed it.

        1. bluefirebrand · · focus · HN ↗
          The big assumption here is that people are either proposers or receivers and never switch roles.

          Which may be largely true for many people but it's definitely not a fixed thing!

          When I was dating, I initiated with a lot of women, but the woman I wound up marrying messaged me first.

          1. yurish · · focus · HN ↗
            This assumption is built-in for Gale-Shapley algorithm.
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