Program 23RD in C++ VERSION 2

PROBLEM STATEMENT :

What is the diameter of a tree?

SOLUTION :

#include <iostream.h>

#include <cstdio>

using namespace std;

int flag = 1;

struct node

{

int data;

node *left;

node *right;

};

node* node(int n)

{

struct node* m = (struct node*)malloc(sizeof(struct node));

m->data=n;

m->left=NULL;

m->right=NULL;

return m;

}

int max(int a, int b)

{

return a>b?a:b;

}

int diameter(struct node* n, int* height)

{

int lh=0;

int rh=0;

int ld=0;

int rd=0;

if(n == 0)

{

*height=0;

return 0;

}

if(n->left == 0 && flag == 1)

{

n=n->right;

return diameter(n,height);

}

else if (n->right == 0 && flag == 1)

{

n=n->left;

return diameter(n,height);

}

else

{

flag=0;

}

ld = diameter (n->left,&lh);

rd = diameter (n->right,&rh);

*height=max(lh,rh)+1;

return (max(lh+rh+1,max(ld,rd)));

}

int main()

{

struct node* root = node(0);

root->right=node(1);

root->right->left=node(7);

root->right->right=node(2);

root->right->right->right=node(3);

root->right->right->right->left=node(4);

root->right->right->right->right=node(5);

int height;

cout<<diameter(root,&height);

}