二分探索木の最小値を見つけるためのC++プログラム

二分探索木の最小値を見つけるプログラムです。

アルゴリズム

Begin
   Declare nd as a structure.
   Declare d to the integer datatype.
   Declare pointer lt to the structure nd type.
   Declare pointer lt to the structure nd type.
   Declare function new_nd() to the structure nd type.
   Declare d to the integer datatype.
   Pass them as a parameter.
   Declare pointer nd to the structure nd type.
      Initialize nd = (struct nd*) malloc(sizeof(struct nd)).
   nd->d = d.
   nd->lt = NULL.
   nd->rt = NULL.
   return(nd).
End
Begin
   Declare function add_node() to the structure nd type.
   Declare pointer nd to the structure nd type.
   Declare d to the integer datatype.
   Pass them as a parameter.
   if (nd == NULL) then
      return(new_nd(d)).
   else
      if (d <= nd->d) then
         nd->lt = add_node(nd->lt, d).
   else
      nd->rt = add_node(nd->rt, d).
   return nd.
End
Begin
   Declare minimum_val() function to the integer datatype.
   Declare pointer nd to the structure nd type.
   Pass it as a parameter.
   Declare pointer cur to the structure nd type.
      Initialize cur = nd.
   while (cur->lt != NULL) do
   cur = cur->lt.
   return(cur->d).
   Declare pointer root to the structure nd type.
      Initialize root = NULL.
   root = add_node(root, 54).
   add_node(root, 32).
   add_node(root, 25).
   add_node(root, 45).
   add_node(root, 65).
   add_node(root, 75).
   Print "The Minimum value of the given binary search tree is: ".
   Print the minimum value of binary tree.
   getchar().
End.

例

#include <bits/stdc++.h>
using namespace std;
struct nd {
   int d;
   struct nd* lt;
   struct nd* rt;
};
struct nd* new_nd(int d) {
   struct nd* nd = (struct nd*)
   malloc(sizeof(struct nd));
   nd->d = d;
   nd->lt = NULL;
   nd->rt = NULL;
   return(nd);
}
struct nd* add_node(struct nd* nd, int d) {
   if (nd == NULL)
   return(new_nd(d));
   else {
      if (d <= nd->d)
         nd->lt = add_node(nd->lt, d);
      else
         nd->rt = add_node(nd->rt, d);
      return nd;
   }
}
int minimum_val(struct nd* nd) {
   struct nd* cur = nd;
   while (cur->lt != NULL) {
      cur = cur->lt;
   }
   return(cur->d);
}
int main() {
   struct nd* root = NULL;
   root = add_node(root, 54);
   add_node(root, 32);
   add_node(root, 25);
   add_node(root, 45);
   add_node(root, 65);
   add_node(root, 75);
   cout << "The Minimum value of the given binary search tree is: " << minimum_val(root);
   getchar();
   return 0;
}

出力

The Minimum value of the given binary search tree is: 25