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POSolving Knight's Tour with Backtracking (javascript)
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copied!<p>I am trying to write an algorithm in javascript to solve the Knight's Tour problem using Backtracking, but it doesn't work. Basically, the function is supposed to output an array called <em>visited</em>, which contains the locations of each moves. However, no location is appended to the array, which remains as [[0,0]]. Here is my code. Any clue? </p> <pre><code>var unit = 75; function m1(position) { position[0] += unit; position[1] += 2*unit; return [position[0],position[1]]} function m2(position) { position[0] -= unit; position[1] += 2*unit; return [position[0],position[1]]} function m3(position) { position[0] += 2*unit; position[1] += unit; return [position[0],position[1]]} function m4(position) { position[0] -= 2*unit; position[1] += unit; return [position[0],position[1]]} function m5(position) { position[0] += unit; position[1] -= 2*unit; return [position[0],position[1]]} function m6(position) { position[0] -= unit; position[1] -= 2*unit; return [position[0],position[1]]} function m7(position) { position[0] += 2*unit; position[1] -= unit; return [position[0],position[1]]} function m8(position) { position[0] -= 2*unit; position[1] -= unit; return [position[0],position[1]]} var moves = [m1, m2, m3, m4, m5, m6, m7, m8]; var currentPosition = [0, 0]; var visited = [currentPosition]; function knightour(currentPosition) { var j; if (promising(currentPosition)) { if (visited.length == 64) { return visited; } else { for (j=0; j<moves.length; j++) { context.drawImage(knight, currentPosition[0], currentPosition[1]); alert("NEXT"); visited.push(moves[j](currentPosition)); knightour(currentPosition); } } } } function promising(currentPosition) { if (currentPosition[0] < 600 && currentPosition[0] >= 0 && currentPosition[1] < 600 && currentPosition[1] >= 0 && isVisited(currentPosition, visited)) { return true; } else { return false; } } function isVisited(position, visited) // visited is an array of size n of array of size 2 ([x,y]) { // currentPosition is an array of size 2 ([x,y]) for (var i=0; i<visited.length; i++) { if (position[0] == visited[i][0] && position[1] == visited[i][1]) { return true; } } return false; } </code></pre> <p>Thank you.</p>

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