在C++中用preorder构造树

Question

void HCTree::buildFromHeader(ifstream& in, HCNode* n, int codeToUse) {

   if( bitsToRead > 0) {
      char c = in.get();
      bitsToRead--;
      if(c == '0') {
         n = new HCNode(0, 0, 0, 0, 0, codeToUse);
         if(rootSet == 0) {
            root = n;
            rootSet = true;
         }
         HCNode* left;
         n->c0 = left;
         HCNode* right;
         n->c1 = right;
         buildFromHeader(in, left, 0);
         buildFromHeader(in, right, 1);
      }
      else { 
         byte symbol = in.get();
         n = new HCNode(0, symbol, 0, 0, 0, codeToUse);
         bitsToRead--;
         n->c0 = n->c1 = NULL;
      }
   }
}

Answer 1

似乎在变化

void HCTree::buildFromHeader(ifstream& in, HCNode* n, int codeToUse) {

到

void HCTree::buildFromHeader(ifstream& in, HCNode* &n, int codeToUse) {

会做这项工作。

buildFromHeader(in, root, codeToUse)

HCNode* left;
n->c0 = left;
HCNode* right;
n->c1 = right;
buildFromHeader(in, left, 0);
buildFromHeader(in, right, 1);

buildFromHeader(in, n->c0, 0);
buildFromHeader(in, n->c1, 0);