Created
September 25, 2014 20:10
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| // Permutation | |
| function permute(input) { | |
| var permArr = [], | |
| usedChars = []; | |
| function main(input) { | |
| var i, ch; | |
| for (i = 0; i < input.length; i++) { | |
| ch = input.splice(i, 1)[0]; | |
| usedChars.push(ch); | |
| if (input.length === 0) { | |
| permArr.push(usedChars.slice()); | |
| } | |
| main(input); | |
| input.splice(i, 0, ch); | |
| usedChars.pop(); | |
| } | |
| return permArr; | |
| } | |
| return main(input); | |
| } | |
| // Combinations | |
| var follows, combinations; | |
| follows = function(a) { | |
| return a.map(function(item, i) { | |
| return [item, follows(a.slice(i+1))]; | |
| }); | |
| }; | |
| combinations = function(a) { | |
| var combs = function(prefix, trie, result) { | |
| trie.forEach(function(node, i) { | |
| result.push((prefix + ' ' + node[0]).trim()); | |
| combs(prefix + ' ' + node[0], node[1], result); | |
| }); | |
| // return result; | |
| // return result.sort(function(a,b){return b-a}); | |
| return result.sort(function(a,b){return b.length - a.length;}); | |
| }; | |
| return combs('', follows(a), []); | |
| }; | |
| console.log('Permutation', permute([5, 3, 7, 1])); | |
| console.log('Combination', combinations([5, 3, 7, 1])); |
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