Adding support for building wavelet trees using uchar arrays

[SXSI/XMLTree.git] / libcds / src / static_sequence / wt_node_internal.cpp

diff --git a/libcds/src/static_sequence/wt_node_internal.cpp b/libcds/src/static_sequence/wt_node_internal.cpp
index b4727a3..d2d0fa8 100644 (file)
--- a/libcds/src/static_sequence/wt_node_internal.cpp
+++ b/libcds/src/static_sequence/wt_node_internal.cpp
@@ -70,6 +70,56 @@ wt_node_internal::wt_node_internal(uint * symbols, uint n, uint l, wt_coder * c,
        delete [] right;
 }
 
+wt_node_internal::wt_node_internal(uchar * symbols, uint n, uint l, wt_coder * c, static_bitsequence_builder * bmb) {
+       uint * ibitmap = new uint[n/W+1];
+       for(uint i=0;i<n/W+1;i++)
+               ibitmap[i]=0;
+       for(uint i=0;i<n;i++) 
+               if(c->is_set((uint)symbols[i],l))
+                       bitset(ibitmap,i);
+       bitmap = bmb->build(ibitmap, n);
+  delete [] ibitmap;
+       uint count_right = bitmap->rank1(n-1);
+       uint count_left = n-count_right+1;
+       uchar * left = new uchar[count_left+1];
+       uchar * right = new uchar[count_right+1];
+       count_right = count_left = 0;
+       bool match_left = true, match_right = true;
+       for(uint i=0;i<n;i++) {
+               if(bitmap->access(i)) {
+                       right[count_right++]=symbols[i];
+                       if(count_right>1)
+                               if(right[count_right-1]!=right[count_right-2])
+                                       match_right = false;
+               }
+               else {
+                       left[count_left++]=symbols[i];
+                       if(count_left>1)
+                               if(left[count_left-1]!=left[count_left-2])
+                                       match_left = false;
+               }
+       }
+       if(count_left>0) {
+               if(match_left/* && c->done(left[0],l+1)*/)
+                       left_child = new wt_node_leaf((uint)left[0], count_left);
+               else
+                       left_child = new wt_node_internal(left, count_left, l+1, c, bmb);
+       } else {
+               left_child = NULL;
+       }
+       if(count_right>0) {
+               if(match_right/* && c->done(right[0],l+1)*/)
+                       right_child = new wt_node_leaf((uint)right[0], count_right);
+               else
+                       right_child = new wt_node_internal(right, count_right, l+1, c, bmb);
+       } else {
+               right_child = NULL;
+       }
+       delete [] left;
+       delete [] right;
+}
+
+
 wt_node_internal::wt_node_internal() { }
 
 wt_node_internal::~wt_node_internal() {