forked from Mirror/wren
61 lines
1.2 KiB
Dart
61 lines
1.2 KiB
Dart
// Ported from the Wren version.
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class Tree {
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var _item;
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var _left;
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var _right;
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Tree(item, depth) {
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_item = item;
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if (depth > 0) {
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var item2 = item + item;
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depth--;
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_left = new Tree(item2 - 1, depth);
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_right = new Tree(item2, depth);
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}
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}
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get check {
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if (_left == null) {
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return _item;
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}
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return _item + _left.check - _right.check;
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}
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}
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main() {
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var minDepth = 4;
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var maxDepth = 12;
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var stretchDepth = maxDepth + 1;
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Stopwatch watch = new Stopwatch();
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watch.start();
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print("stretch tree of depth ${stretchDepth} check: "
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"${new Tree(0, stretchDepth).check}");
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var longLivedTree = new Tree(0, maxDepth);
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// iterations = 2 ** maxDepth
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var iterations = 1;
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for (var d = 0; d < maxDepth; d++) {
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iterations = iterations * 2;
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}
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var depth = minDepth;
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while (depth < stretchDepth) {
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var check = 0;
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for (var i = 1; i <= iterations; i++) {
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check += new Tree(i, depth).check + new Tree(-i, depth).check;
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}
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print("${iterations * 2} trees of depth ${depth} check: ${check}");
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iterations ~/= 4;
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depth += 2;
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}
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print("long lived tree of depth ${maxDepth} check: ${longLivedTree.check}");
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print("elapsed: ${watch.elapsedMilliseconds / 1000}");
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}
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