Created
June 10, 2014 14:24
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| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <meta charset="utf-8"> | |
| <title>JS Bin</title> | |
| </head> | |
| <body> | |
| </body> | |
| </html> |
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| /** | |
| * Utilities | |
| */ | |
| function now(){ | |
| return performance && | |
| performance.now ? function now() { | |
| return performance.now() | |
| } : Date.now || function now() { | |
| return +new Date | |
| } | |
| } | |
| // http://stackoverflow.com/questions/23095637/how-do-you-do-a-random-rbg-in-javascript | |
| function getRandomRgb() { | |
| var num = Math.round(0xffffff * Math.random()); | |
| var r = num >> 16; | |
| var g = num >> 8 & 255; | |
| var b = num & 255; | |
| return [r,g,b]; | |
| } | |
| // ======================================== | |
| /** | |
| * Pixel | |
| * | |
| * @param r {String|int} red | |
| * @param g {String|int} green | |
| * @param b {String|int} blue | |
| * @param a {String|int} alpha channel | |
| * | |
| * @returns {Array} Pixel of [r,g,b,a] | |
| */ | |
| function Pixel(r, g, b, a){ | |
| return [r|0,g|0,b|0,a|0]; | |
| } | |
| /** | |
| * Image | |
| * | |
| * @param x {String|int} Length | |
| * @param y {String|int} Width | |
| * | |
| * @returns {Array} An 2d image array | |
| */ | |
| function Image(x, y){ | |
| var image = []; | |
| for (var i = 0; i < x; i++){ | |
| image[i] = []; | |
| for (var j = 0; j < y; j++){ | |
| var rgb = getRandomRgb(); | |
| image[i][j] = Pixel(rgb[0],rgb[1],rgb[2],255); | |
| } | |
| } | |
| return image; | |
| } | |
| // ======================================== | |
| /** | |
| * Algorithms | |
| */ | |
| // naive as fuck | |
| function naive_equals(image1, image2){ | |
| // assuming this is a parallelogram. | |
| var x0_length = image1.length, | |
| y0_length = image1[0].length, | |
| x1_length = image2.length, | |
| y1_length = image2[0].length; | |
| var result = true; | |
| for (var i = 0; i < x0_length; i++){ | |
| for (var j = 0; j < y0_length; j++){ | |
| return image1[i][j] == image2[i][j] && true; | |
| } | |
| } | |
| } | |
| // ======================================== | |
| // Go-go-gadget image duplicate detector! | |
| function __main__(equals){ | |
| var image1 = Image(100,100), | |
| image2 = Image(100,100); | |
| var start = now()(), | |
| end; | |
| var result = equals(image1, image1); | |
| end = now()(); | |
| console.log('========================================'); | |
| console.log('equals: ' + result); | |
| console.log('elapsed (ms): ' + parseFloat((end - start))); | |
| } | |
| __main__(naive_equals); |
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