A function that will take a tree as argument and return the number of ints that were typed?

Question

I need a function in my project that will take a tree as argument and return the number of integers that were typed and a correct call.

wouldn't it just be preorder? like below. Please. Thanks

#include "t.h"
void preorder(tnode * t){
if (t == NULL) return;
cout << t->info <<endl;
preorder(t->left);
preorder(t->right);
}

call would be preorder(t).

This is the original function i have

 #ifndef T_H

#define T_H

#include <iostream>
#include <iomanip>
using namespace std;

struct tnode {
    int info ;
    int count;
    tnode * right, *left;
};

tnode * insert(int target,tnode * t);
tnode * makenode(int x);
tnode * tsearch(int x,tnode * t);
void inorder(tnode * t);
int height(tnode * t);
int count(tnode * t) ;
int total(tnode * t) ;

#endif

int main() {
int n,c;
tnode * t = NULL, *x;
    while (cin >> n) {t=insert(n,t);cout << n <<' ';}
    cout << endl;
    inorder(t);
    cout << endl;
    c = count(t);
    cout << "count: "<< c  <<endl;
    cout << endl;
    c = height(t);
    cout << "height: "<< c  <<endl;
    cout << endl;
    c=200;
    while (c-->0) if (x = tsearch(c,t)) cout << c << " is on the tree."<<endl;
return 0;
}

#include "t.h"

int count(tnode * t) {
    if (t == NULL) return 0;
    return 1 +  count(t->left) + count (t->right);
}

#include "t.h"

int height(tnode * t) {
    if (t == NULL) return -1;
    return 1 + max(height(t->left) , height (t->right));
}

#include "t.h"

//write out t in order
void inorder(tnode * t) {
    if (t == NULL) return;
    inorder (t->left);//write out lst in order
    cout <<setw(5) << t->info <<setw(5) << t->count<< endl;
    inorder (t->right);//write out rst in order
}

#include "t.h"

tnode * insert(int x, tnode * t) {
tnode * tmp = tsearch(x,t);
if (tmp != NULL) {
    tmp->count++;
    return t;
}
if (t == NULL) return makenode(x);
if ( x < t->info ) {
    t->left = insert(x,t->left);
    return t;
}
t->right = insert(x,t->right);
return t;
}

#include "t.h"

tnode * makenode(int x) {
tnode * t = new tnode;
    t->info =x;
    t->count =1;
    t->right = t->left = NULL;
return t;
}

Answer 1

First, your function can't be void. It has to return the number of ints that were typed, so it has to return int or int*.

Secondly, is the tree a binary tree that has all the ints that were typed? If so, any tree traversal algorithm will do. You just need a variable that you will increment when you find a new node (assuming they all store an int).

int preorder(tnode * t){
  if (t == NULL) return 0;

  else{
     return 1 + preorder(t->left) + preorder(t->right);
  }
}

If t isn't null, then it has 1 int stored in it. Then you just have to check the node's children.

Answer 2

When the user types a number, the insert function either inserts a new node with a count of 1 or adds to the count of an existing node. You need to sum up the counts of the elements in the tree:

int tcount(tnode * t){
    if (t == NULL) return 0;
    return t->count + tcount(t->left) + tcount(t->right);
}

A typical call would be

tnode * root = NULL;

/* insert stuff into the tree */

int count = tcount(root);