59 lines
1.1 KiB
JavaScript
59 lines
1.1 KiB
JavaScript
import { csTdfs } from './csTdfs.js';
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/**
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* Post order a tree of forest
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*
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* @param {Array} parent The tree or forest
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* @param {Number} n Number of columns
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*
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* Reference: http://faculty.cse.tamu.edu/davis/publications.html
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*/
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export function csPost(parent, n) {
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// check inputs
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if (!parent) {
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return null;
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} // vars
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var k = 0;
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var j; // allocate result
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var post = []; // (n)
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// workspace, head: first n entries, next: next n entries, stack: last n entries
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var w = []; // (3 * n)
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var head = 0;
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var next = n;
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var stack = 2 * n; // initialize workspace
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for (j = 0; j < n; j++) {
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// empty linked lists
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w[head + j] = -1;
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} // traverse nodes in reverse order
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for (j = n - 1; j >= 0; j--) {
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// check j is a root
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if (parent[j] === -1) {
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continue;
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} // add j to list of its parent
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w[next + j] = w[head + parent[j]];
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w[head + parent[j]] = j;
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} // loop nodes
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for (j = 0; j < n; j++) {
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// skip j if it is not a root
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if (parent[j] !== -1) {
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continue;
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} // depth-first search
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k = csTdfs(j, k, w, head, next, post, stack);
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}
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return post;
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} |