array_to_binary_tree.c

//array to BT
#include<stdio.h>
#include<stdlib.h>
struct t_node{
	int data;
	struct t_node *left;
	struct t_node *right;
};
typedef struct t_node TreeNode;
void in_order(TreeNode *root){
	if(root!=NULL){
		in_order(root->left);
		printf("%d ",root->data);
		in_order(root->right);
	}
}
TreeNode *create_tree_node(int val){
	TreeNode *nn=(TreeNode *)malloc(sizeof(TreeNode));
	nn->data=val;
	nn->left=NULL;
	nn->right=NULL;
	return nn;
}
TreeNode *constructBT(int *a,int n){
	TreeNode *q[100];
	int front,rear;
	front=rear=0;
	q[rear]=create_tree_node(a[0]);
	rear++;
	int i=0;
	while(1){
		if(2 * i+1>=n){
			break;
		}
		if(2*i+1<n){
			//creating a node with value at 2*i+1 index
			TreeNode *t=create_tree_node(a[2*i+1]);
			q[rear++]=t;//adding it to queue
			q[front]->left=t;//connecting the left child
		}
			if(2*i+2<n){
			//creating a node with value at 2*i+2 index
			TreeNode *t=create_tree_node(a[2*i+2]);
			q[rear++]=t;//adding it to queue
			q[front]->right=t;//connecting the right child
		}
		front++;
		i++;
	}
	return q[0];//root of constructed binary tree
}
int main(){
	int n;
	printf("enter the size of array:");
	scanf("%d",&n);
	int a[n];
	printf("enter the array elements:\n");
	int i;
	for( i=0;i<n;i++){
		scanf("%d",&a[i]);
	}
	//RETURN THE ROOT OF THE  created BINARY TREE 
	TreeNode *root=constructBT(a,n);
	//checking the tree
	in_order(root);
}