This is a Binary-Search Tree template written by Leon.

``` cpp Binary Search Tree

#include #include #include //Binary Search Tree //Created by Leon //Oct 19, 2009 using namespace std;

struct tree { int key; int value; tree *l, *r; };

tree* Insert(tree* t, int c) { tree *nt = new tree(); nt->l = 0, nt->r = 0, nt->value = 1; nt->key = c; if (t == 0) { return nt; } tree *tmp = t; tree *p; while (tmp != 0 && tmp->key != c) { p = tmp; if (tmp->key < c) { tmp = tmp->r; } else { tmp = tmp->l; } } if (tmp == 0) { tmp = nt; if (p->key < c) { p->r = tmp; } else { p->l = tmp; } } else { tmp->value++; } return t; }

void InOrder(tree* t) { if (t != 0) { InOrder(t->l); printf(“%d %dn”, t->key, t->value); InOrder(t->r); } }

int main() { tree* root = 0; root = Insert(root, 3); root = Insert(root, 19); root = Insert(root, 2); root = Insert(root, 5); root = Insert(root, 2); InOrder(root); return 0; }

```