Forming a binary tree from given array of integers.

/*I am trying to form a binary tree from an array of ints. The given code has some flaws.Please help 
in resolving them.I am using an array"addr[]" to store the addresses of various nodes according to 
their position in the tree.*/


#include<stdio.h>
#include<stdlib.h>

typedef struct Node{
    int info;
    struct node *left;
    struct node *right;
}node;

void form_tree(int a[],node **root)
{
    int addr[100];
    int i;
    node *ptr;
    (*root)->info=a[0];
    (*root)->left=NULL;
    (*root)->right=NULL;
    addr[0]=-1;
    addr[1]=root;
    for(i=1;i<10;i++)
    {
        node *nw=(node*)malloc(sizeof(node));
        nw->info=a[i];
        nw->left=NULL;
        nw->right=NULL;
        addr[i+1]=&nw;
        ptr=addr[(i+1)/2];
        if((i+1)%2==0)
        ptr->left=&nw;
        else
        ptr->right=&nw;
    }   
}

int main()
{
    node *ptr;
    int a[10]={5,10,15,20,25,30,35,40,45,50};
    node *root;
    root=(node*)malloc(sizeof(node));
    form_tree(a,&root);
    ptr=root;
    while(ptr->left!=NULL)
    printf("\n%d",ptr->info); 
    getch();
}