simplify # trees: Catalan trees -> Wedderburn–Etherington trees

tree.c

@@ -194,41 +194,49 @@ NODE *dup_node(src)
     return dst;
 }
 
-/*void free_node(node)
+/* untested - unused */
+int calc_prof_node(node)
     NODE *node;
 {
+    int left, right;
+
     if (node->type==TREE_LEAF) {
-        node->next=freenodes;
-        freenodes=node;
+        return 0;
     } else {
-        free_node(node->left);
-        free_node(node->right);
-        node->next=freenodes;
-        freenodes=node;
+        left=calc_prof_node(node->left);
+        right=calc_prof_node(node->right);
+        node->prof=MAX(left, right)+1;
     }
-    }*/
+    return node->prof;
+}
 
 NODE *build_tree(desc, size)
-    int *desc;
+    char *desc;
     int size;
 {
     NODE *root, *node;
     NODE *nodestack[1024];      /* TODO: make it dynamic */
     int i, curnode=0;
 
+#   ifdef DEBUG_TREE
+    printf("tree %d desc=", ntrees);
+    for (i=0; i<size; ++i)
+        printf("%c", desc[i]);
+    putchar('\n');
+#   endif
     root=get_node();
     root->type=TREE_NODE;
     nodestack[curnode++]=root;
 
     for(i=1; i<size; ++i) {
         node = get_node();
-        if (desc[i-1]) {
+        if (desc[i-1]=='1') {
             nodestack[curnode-1]->left = node;
         } else {
             nodestack[curnode-1]->right = node;
             curnode--;
         }
-        if (desc[i]) {
+        if (desc[i]=='1') {
             node->type=TREE_NODE;
             nodestack[curnode++]=node;
         } else {
@@ -239,25 +247,102 @@ NODE *build_tree(desc, size)
     return root;
 }
 
-void gen_tree(seq, n, nb1, nb0)
-    int *seq;
-    int n;                      /* number of nodes */
-    int nb1;                    /* number of "1" */
-    int nb0;                    /* number of "0" */
+/* generate reduced trees from static description */
+void gen_reduced_trees(n)
+    int n;
+{
+    int size=n*2-1, i;
+    TREE *tree;
+    char name[80];
+    char *seq2[]= {
+        "100"
+    };
+    char *seq3[]= {
+        "10100"
+    };
+    char *seq4[]= {
+        "1010100",
+        "1100100"
+    };
+    char *seq5[]= {
+        "101010100",
+        "110010100",
+        "101100100"
+    };
+    char *seq6[]= {
+        "10101010100",
+        "11001010100",
+        "10110010100",
+        "10101100100",
+        "11001100100",
+        "11010010100"
+    };
+
+    if (n<2 || n>MAXINPUT) {
+        fprintf(stderr, "gen_reduced_trees: wrong leaves %d\n", n);
+        return;
+    }
+#   ifdef DEBUG_TREE
+    printf("gen_reduced_trees(leaves=%d)\n", n);
+#   endif
+
+    switch (n) {
+        case 2:
+            ntrees++;
+            sprintf(name, "Tree %d", ntrees);
+            tree=new_tree(name);
+            tree->head=build_tree(seq2[0], size);
+            break;
+        case 3:
+            ntrees++;
+            sprintf(name, "Tree %d", ntrees);
+            tree=new_tree(name);
+            tree->head=build_tree(seq3[0], size);
+            break;
+        case 4:
+            for (i=0; i<2; ++i) {
+                ntrees++;
+                sprintf(name, "Tree %d", ntrees);
+                tree=new_tree(name);
+                tree->head=build_tree(seq4[i], size);
+            }
+            break;
+        case 5:
+            for (i=0; i<3; ++i) {
+                ntrees++;
+                sprintf(name, "Tree %d", ntrees);
+                tree=new_tree(name);
+                tree->head=build_tree(seq5[i], size);
+            }
+            break;
+        case 6:
+            for (i=0; i<6; ++i) {
+                ntrees++;
+                sprintf(name, "Tree %d", ntrees);
+                tree=new_tree(name);
+                tree->head=build_tree(seq6[i], size);
+            }
+            break;
+    }
+    return;
+}
+
+void gen_tree(seq, n, nb1, nb0)
+    char *seq;
+    int n;                                        /* number of nodes */
+    int nb1;                                      /* number of "1" */
+    int nb0;                                      /* number of "0" */
 {
-    int i;
     char name[80];
     TREE *tree;
 
-    if((nb1 + nb0) == 2*n) {   /* end */
-        seq[2*n] = 0;
+#   ifdef DEBUG_TREE
+    printf("gen_tree(n=%d, nb1=%d, nb0=%d)\n", n, nb1, nb0);
+#   endif
+    if((nb1 + nb0) == 2*n) {                      /* end */
+        seq[2*n] = '0';
+        seq[2*n+1] = 0;
         ntrees++;
-#       ifdef DEBUG1
-        printf("tree %d desc=", ntrees);
-        for (i=0; i<=2*n; ++i)
-            printf("%d", seq[i]);
-        putchar('\n');
-#       endif
         sprintf(name, "Tree %d", ntrees);
         tree=new_tree(name);
         tree->head=build_tree(seq, 2*n+1);
@@ -265,12 +350,12 @@ void gen_tree(seq, n, nb1, nb0)
     }
 
     if(nb1 >= nb0 && nb1 < n) {
-        seq[nb1+nb0] = 1;
+        seq[nb1+nb0] = '1';
         gen_tree(seq, n, nb1+1, nb0);
     }
 
     if(nb0 < nb1 && nb1 <=n) {
-        seq[nb1+nb0] = 0;
+        seq[nb1+nb0] = '0';
         gen_tree(seq, n, nb1, nb0+1);
     }
 }
@@ -292,13 +377,13 @@ int n_trees()
 }
 
 #ifdef STANDALONE
-main(ac, av)
+void main(ac, av)
     int ac;
     char **av;
 {
     int n, details=0;
+    char array[1024];
 
-    int array[1024];
     if (ac<2 || ac>3) {
         fprintf(stderr, "usage: %s nodes [type]\n", *av);
         fprintf(stderr, "type can be 0 (RPN, default, 1 (polish), 2 (details), 3 (lisp notation), 4 (parenthesed notation)\n");
@@ -308,7 +393,8 @@ main(ac, av)
         details=atoi(av[2]);
     }
     n=atoi(av[1]);
-    gen_tree(array, n, 0, 0);
+    gen_reduced_trees(n+1);
+    //gen_tree(array, n, 0, 0);
     print_trees(details);
     exit(0);
 }