73 lines
No EOL
1.5 KiB
JavaScript
73 lines
No EOL
1.5 KiB
JavaScript
function doit() {
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function make_x_first(x,y) {
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return {x, y};
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}
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function make_y_first(x, y) {
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return {y, x};
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}
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function make_random(x, y) {
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if (Math.random() > 0.5) {
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return make_y_first(x, y);
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} else {
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return make_x_first(x, y);
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}
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}
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const million = 1000 * 1000;
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const n = 10 * million;
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function bulk(filler) {
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let a = [];
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for (let i = 0; i < n; i++) {
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a.push(filler(i, i * i));
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}
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return a;
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}
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const x_first = bulk(make_x_first);
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const y_first = bulk(make_y_first);
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const mixed = bulk(make_random);
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function time(func) {
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const start = Date.now();
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func();
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const delta = Date.now() - start;
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return delta;
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}
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function report(func) {
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let delta = time(func);
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console.log(`${delta} ms`);
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}
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function demo(dataSet) {
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for (let i = 0; i < 3; i++) {
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console.log(`run ${i+1}`);
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report(() => {
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let sumX = 0, sumY = 0;
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for (let i = 0; i < dataSet.length; i++) {
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let item = dataSet[i];
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sumX += item.x;
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sumY += item.y;
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}
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return {x: sumX, y: sumY};
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});
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console.log(``);
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}
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}
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console.log(`** x_first`);
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demo(x_first);
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console.log(`** y_first`);
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demo(y_first);
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console.log(`** mixed`);
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demo(mixed);
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}
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doit(); |