simple-squiggle

A restricted subset of Squiggle
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csTdfs.js (1228B)


      1 /**
      2  * Depth-first search and postorder of a tree rooted at node j
      3  *
      4  * @param {Number}  j               The tree node
      5  * @param {Number}  k
      6  * @param {Array}   w               The workspace array
      7  * @param {Number}  head            The index offset within the workspace for the head array
      8  * @param {Number}  next            The index offset within the workspace for the next array
      9  * @param {Array}   post            The post ordering array
     10  * @param {Number}  stack           The index offset within the workspace for the stack array
     11  *
     12  * Reference: http://faculty.cse.tamu.edu/davis/publications.html
     13  */
     14 export function csTdfs(j, k, w, head, next, post, stack) {
     15   // variables
     16   var top = 0; // place j on the stack
     17 
     18   w[stack] = j; // while (stack is not empty)
     19 
     20   while (top >= 0) {
     21     // p = top of stack
     22     var p = w[stack + top]; // i = youngest child of p
     23 
     24     var i = w[head + p];
     25 
     26     if (i === -1) {
     27       // p has no unordered children left
     28       top--; // node p is the kth postordered node
     29 
     30       post[k++] = p;
     31     } else {
     32       // remove i from children of p
     33       w[head + p] = w[next + i]; // increment top
     34 
     35       ++top; // start dfs on child node i
     36 
     37       w[stack + top] = i;
     38     }
     39   }
     40 
     41   return k;
     42 }