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Traversals of trees.cpp
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Traversals of trees.cpp
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#include<bits/stdc++.h>
#define ll long long
#define MAX 1000003
#define V vector<int>
#define pii pair<int,int>
#define VP vector< pii >
#define MOD 1000000007
#define mp make_pair
#define pb push_back
#define rep(i,a,b) for(int (i) = (a); (i) < (b); (i)++)
#define all(v) (v).begin(),(v).end()
#define S(x) scanf("%d",&(x))
#define S2(x,y) scanf("%d%d",&(x),&(y))
#define SL(x) scanf("%lld",&(x))
#define SL2(x) scanf("%lld%lld",&(x),&(y))
#define test() ll t;cin>>t;while(t--)
#define P(x) printf("%d\n",(x))
#define FF first
#define SS second
using namespace std;
struct node {
int data;
struct node *left;
struct node *right;
};
struct node *newNode(int data) {
struct node *treeNode = new node;
treeNode->data = data;
treeNode->left = NULL;
treeNode->right = NULL;
return treeNode;
}
int heightTree(struct node *root) {
if(root == NULL) return 0;
int lDepth = heightTree(root->left);
int rDepth = heightTree(root->right);
if(lDepth > rDepth) return lDepth+1;
else return rDepth+1;
}
void inOrder(struct node *root) {
if(root == NULL) return;
inOrder(root->left);
cout<< root->data;
inOrder(root->right);
}
void preOrder(struct node *root) {
if(root == NULL) return;
cout<<root->data;
preOrder(root->left);
preOrder(root->right);
}
void postOrder(struct node *root) {
if(root == NULL) return;
postOrder(root->left);
postOrder(root->right);
cout<<root->data;
}
void printGivenLevel(struct node *root,int i){
if(root == NULL) return;
if(i == 1) cout<< root->data;
printGivenLevel(root->left, i-1);
printGivenLevel(root->right, i-1);
}
void levelOrder(struct node *root) {
int h = heightTree(root);
for(int i=1;i<h;i++) {
printGivenLevel(root, i);
}
}
void levelOrderUsingQueue(struct node *root) {
if(root == NULL) return;
queue<struct node *> q;
q.push(root);
while(!q.empty()) {
struct node *temp = q.front();
cout<< temp->data<<" ";
if(temp->left!=NULL) q.push(temp->left);
if(temp->right!=NULL) q.push(temp->right);
q.pop();
}
}
int main(){
/*
1
/ \
2 3
/ \
4 5
/
6
*/
// struct node *root = newNode(1);
// root->left = newNode(2);
// root->right = newNode(3);
// root->left->left = newNode(4);
// root->left->right = newNode(6);
// root->right->right = newNode(5);
struct node *root = newNode(1);
root->left = newNode(2);
root->right = newNode(3);
root->left->left = newNode(4);
root->left->right = newNode(5);
root->left->right->left = newNode(6);
cout<< "In-order: ";
inOrder(root);
cout<<endl;
cout<< "Pre-order: ";
preOrder(root);
cout<<endl;
cout<< "Post-order: ";
postOrder(root);
cout<<endl;
cout<< "Level-Order (BFS): In O(n^2) ";
levelOrder(root);
cout<<endl;
cout<< "Level-Order (BFS): Using queue in O(n) ";
levelOrder(root);
cout<<endl;
return 0;
}
/*
Code by :
Rishabh Patel
Integrated Post Graduation (IPG)
Indian Institute of Information Technology and Management, Gwalior (ABV-IIITM Gwalior)
In order to understand recursion, one must first understand recursion.
*/