--- id: 5a23c84252665b21eecc8024 title: Desafio do nome do estado challengeType: 5 forumTopicId: 302323 dashedName: state-name-puzzle --- # --description-- Esta tarefa é inspirada na coluna "Wordplay", de Mark Nelson no DDJ e um dos desafios semanais de Will Shortz na edição de fim de semana da NPR [\[1\]](https://www.npr.org/templates/story/story.php?storyId=9264290), sendo originalmente atribuída a David Edelheit. O desafio era pegar os nomes de dois estados dos Estados Unidos, misturá-los e, então, reorganizar as letras para formar os nomes de dois estados *diferentes* (de modo que os quatro nomes de estados sejam diferentes entre eles). Que estados são esses? O problema foi publicado novamente na [Unicon Discussion Web](https://tapestry.tucson.az.us/twiki/bin/view/Main/StateNamesPuzzle), que inclui diversas soluções com a análise. Várias técnicas podem ser úteis caso você queira consultar, como: [a numeração de Gödel](https://en.wikipedia.org/wiki/Goedel_numbering), [as relações de equivalência](https://en.wikipedia.org/wiki/Equivalence_relation) e [as classes de equivalência](https://en.wikipedia.org/wiki/Equivalence_classes). Os méritos básicos destas técnicas foram discutidos na Unicon Discussion Web. Foi também apresentado um segundo desafio, sob a forma de um conjunto de novos estados fictícios. # --instructions-- Escreva uma função para resolver o desafio para o array de nomes de estados fornecido. A função deve retornar um array. Cada elemento deve ser um objeto neste formato: `{"from":[],"to":[]}`. O array "from" deve conter os nomes originais e o array "to" deve conter os nomes resultantes. # --hints-- `solve` deve ser uma função. ```js assert(typeof solve == 'function'); ``` `solve(["New Mexico", "New York", "North Carolina ", "North Dakota", "Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island", "South Carolina", "South Dakota"])` deve retornar um array. ```js assert( Array.isArray( solve([ 'New Mexico', 'New York', 'North Carolina ', 'North Dakota', 'Ohio', 'Oklahoma', 'Oregon', 'Pennsylvania', 'Rhode Island', 'South Carolina', 'South Dakota' ]) ) ); ``` `solve(["New Mexico", "New York", "North Carolina ", "North Dakota", "Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island", "South Carolina", "South Dakota"])` deve retornar `[{ from: ["North Carolina ", "South Dakota"], to: ["North Dakota", "South Carolina"] }]`. ```js assert.deepEqual( solve([ 'New Mexico', 'New York', 'North Carolina ', 'North Dakota', 'Ohio', 'Oklahoma', 'Oregon', 'Pennsylvania', 'Rhode Island', 'South Carolina', 'South Dakota' ]), [ { from: ['North Carolina ', 'South Dakota'], to: ['North Dakota', 'South Carolina'] } ] ); ``` `solve(["New York", "New Kory", "Wen Kory", "York New", "Kory New", "New Kory"])` deve retornar `[{ from: ["New Kory", "New York"], to: ["Wen Kory", "York New"] }, { from: ["New Kory", "New York"], to: ["Kory New", "Wen Kory"] }, { from: ["New Kory", "New York"], to: ["Kory New", "York New"] }, { from: ["New York", "Wen Kory"], to: ["New Kory", "York New"] }, { from: ["New York", "Wen Kory"], to: ["Kory New", "New Kory"] }, { from: ["New York", "Wen Kory"], to: ["Kory New", "York New"] }, { from: ["New York", "York New"], to: ["New Kory", "Wen Kory"] }, { from: ["New York", "York New"], to: ["Kory New", "New Kory"] }, { from: ["New York", "York New"], to: ["Kory New", "Wen Kory"] }, { from: ["Kory New", "New York"], to: ["New Kory", "Wen Kory"] }, { from: ["Kory New", "New York"], to: ["New Kory", "York New"] }, { from: ["Kory New", "New York"], to: ["Wen Kory", "York New"] }, { from: ["New Kory", "Wen Kory"], to: ["Kory New", "York New"] }, { from: ["New Kory", "York New"], to: ["Kory New", "Wen Kory"] }, { from: ["Kory New", "New Kory"], to: ["Wen Kory", "York New"] }]`. ```js assert.deepEqual( solve([ 'New York', 'New Kory', 'Wen Kory', 'York New', 'Kory New', 'New Kory' ]), [ { from: ['New Kory', 'New York'], to: ['Wen Kory', 'York New'] }, { from: ['New Kory', 'New York'], to: ['Kory New', 'Wen Kory'] }, { from: ['New Kory', 'New York'], to: ['Kory New', 'York New'] }, { from: ['New York', 'Wen Kory'], to: ['New Kory', 'York New'] }, { from: ['New York', 'Wen Kory'], to: ['Kory New', 'New Kory'] }, { from: ['New York', 'Wen Kory'], to: ['Kory New', 'York New'] }, { from: ['New York', 'York New'], to: ['New Kory', 'Wen Kory'] }, { from: ['New York', 'York New'], to: ['Kory New', 'New Kory'] }, { from: ['New York', 'York New'], to: ['Kory New', 'Wen Kory'] }, { from: ['Kory New', 'New York'], to: ['New Kory', 'Wen Kory'] }, { from: ['Kory New', 'New York'], to: ['New Kory', 'York New'] }, { from: ['Kory New', 'New York'], to: ['Wen Kory', 'York New'] }, { from: ['New Kory', 'Wen Kory'], to: ['Kory New', 'York New'] }, { from: ['New Kory', 'York New'], to: ['Kory New', 'Wen Kory'] }, { from: ['Kory New', 'New Kory'], to: ['Wen Kory', 'York New'] } ] ); ``` # --seed-- ## --seed-contents-- ```js function solve(input) { } ``` # --solutions-- ```js function solve(input) { var orig = {}; input.forEach(function(e) { orig[__helpers.removeWhiteSpace(e).toLowerCase()] = e; }); input = Object.keys(orig); var map = {}; for (var i = 0; i < input.length - 1; i++) { var pair0 = input[i]; for (var j = i + 1; j < input.length; j++) { var pair = [pair0, input[j]]; var s = pair0 + pair[1]; var key = s.split('').sort(); var val = map[key] ? map[key] : []; val.push(pair); map[key] = val; } } var result = []; Object.keys(map).forEach(key => { for (var i = 0; i < map[key].length - 1; i++) { var a = map[key][i]; for (var j = i + 1; j < map[key].length; j++) { var b = map[key][j]; if (new Set([a[0], b[0], a[1], b[1]]).size < 4) continue; var from = [orig[a[0]], orig[a[1]]].sort(); var to = [orig[b[0]], orig[b[1]]].sort(); result.push({ from, to }); } } }); return result; } ```