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
Edwin Dodgson priest in 1874, and served his first curacy at Odd Rode in the Diocese of Chester. Following this he served as curate at Helmsley (1875-1877), and at All Saints, Shrewsbury (1877-1879). His subsequent ministry was one of self-sacrifice and dedication, marred by ill health and depression. Dodgson was appointed as Principal of the (UMCA) Kiungani School in Zanzibar in 1879, where he served under Bishop Edward Steere. However, as his brother Charles noted, "the ague was too much for him there". In 1880 he was appointed by the Society for the Propagation of the Gospel (SPG) as missionary and school