Dodgson's method of swaps needed to make him a winner) is an NP-complete problem by reduction from Exact Cover by 3-Sets (X3C). Dodgson's method Dodgson's method is an electoral system proposed by the author, mathematician and logician Charles Dodgson, better known as Lewis Carroll. The method is to extend the Condorcet method by swapping candidates until a Condorcet winner is found. The winner is the candidate which requires the minimum number of swaps. Dodgson proposed this voting scheme in his 1876 work "A method of taking votes on more than two issues". Given an integer "k" and an election, it is NP-complete
Charles Dodgson (priest) College, Oxford, and who was a friend of Dodgson, used to walk over to visit Daresbury on Sundays, sometimes helping with the church services. Bayne would bring his son Vere, who became a lifelong friend of the young Charles Lutwidge. Other friends and visitors included Richard Durnford, Rector of Middleton, Lancashire; Francis Egerton, Member of Parliament for South Lancashire and John Wilson Patten, MP for North Lancashire. Dodgson was concerned about the canal workers on the Bridgewater Canal running past his parish. Together with Egerton, who was a wealthy local landowner, he converted a barge into a floating chapel, moored