IoT C++ 09/24 - Binary Search Tree Example (String)

#include<iostream>
#include<cstdlib>
#include<cstring>
#define NULL __null

using namespace std;

typedef struct treenode {
    string data;
    struct treenode* left;
    struct treenode* right;
} treenode;

treenode* input(treenode* node, char* data)
{
    if(node == NULL){
        treenode* word;
        cout<<"[node] ";
        word = new treenode[100];
        word->data = data;
        word->left = NULL;
        word->right = NULL;
        return word;
    }
    else if(node->data.compare(data) > 0){
    //else if (data < node->data){
        cout<<"[left] ";
        node->left = input(node->left,data);
    }
    else if(node->data.compare(data) < 0){
        cout<<"[right] ";
        node->right = input(node->right,data);
    }
    else{
        cout<<endl<<"ERROR>Already Reegistered";
        return node;
    }
}

void preorder(treenode* node)
{
    cout<<node->data<<" ";
    if (node->left) preorder(node->left);
    if (node->right) preorder(node->right);
}

void ctrorder(treenode* node)
{
    if (node->left) ctrorder(node->left);
    cout<<node->data<<" ";
    if (node->right) ctrorder(node->right);
}

void lstorder(treenode* node)
{
    if (node->right) lstorder(node->right);
    cout<<node->data<<" ";
    if (node->left) lstorder(node->left);
    /*
    if (node->left) lstorder(node->left);
    if (node->right) lstorder(node->right);
    cout<<node->data<<" ";*/
}

void search(treenode* node , char* data)
{
    if(node == NULL){
        cout<<"ERROR>NOT FOUND!"<<endl;
        return;
    }
    else if(data == node->data) {
        cout<<"CENTRE WORD>"<<node->data<<endl;
        cout<<"LEFT WORD>";
        if(node->left!=NULL) cout<<node->left->data<<endl;
        else cout<<"!None?"<<endl;
        cout<<"RIGHT WORD>";
        if(node->right!=NULL) cout<<node->right->data<<endl;
        else cout<<"!None?"<<endl;
        //return;
    }
    else if (data < node->data) {
        search(node->left,data);
    }
    else if (data > node->data) {
        search(node->right,data);
    }
    else {
      cout<<"Error>SEARCH ERROR!"<<endl;
    }
}
void delnum(treenode* node , char* data, char* key)
{
    if(node->data.compare(data) == 0) {
        if(strcmp(data,key)==0){
            cout<<"ERROR>NO! DEL 1STCTR WORD"<<endl;
        }
        else{
            //node->data = "/0";
            node->data = "";
            if(node->left!=NULL) node->left = NULL;
            if(node->right!=NULL) node->right = NULL;
            if(node->data.empty())
                cout<<"Msg>DELETE OK!"<<endl;
            else
                cout<<"Error>NUMDEL ERROR!"<<endl;
        }
    }
    else if (node->data.empty()){
        cout<<"Error>NOT FOUND!"<<endl;
        return;
    }
    else if (node->data.compare(data) > 0) {
        delnum(node->left,data,key);
    }
    else if (node->data.compare(data) < 0) {
        delnum(node->right,data,key);
    }
    else {
     cout<<"Error>NUMDEL ERROR!"<<endl;
    }
}


int main(void)
{
    char word[100]; int select;
    treenode* node;
    node=NULL;
    cout<<"1STCTR>"; cin>>word;
    char key[100]; strcpy(key,word);
    cout<<"Process>";
    node = input(node,word);
    //cout<<endl;
    while(1)
    {
        cout<<endl<<"Input(OUT:-1)>"; cin>>word;
        if(strcmp(word,"-1")==0) break;
        cout<<"Process>";
        input(node,word);
    }
    while(2)
    {
        cout<<"Menu> 1)ALLVIEW, 2)SELECT_VIEW, 3)ADDSTR, 4)DELETE, 5)EXIT"<<endl;
        cout<<"Select>"; cin>>select;
        if(cin.fail())
        {
            cout<<"ERROR>Invalid Select"<<endl;
            //cout<<"Error>PLZ ENTER NUM! NOT CHAR!"<<endl;
            cin.clear(); cin.ignore(256,'\n');
        }
        else if(select==5) break;
        else{
            cin.clear(); cin.ignore(256,'\n');
            switch(select)
            {
                case 1:
                    cout<<"pre>"; preorder(node); cout<<endl;
                    cout<<"ctr>"; ctrorder(node); cout<<endl;
                    cout<<"lst>"; lstorder(node); cout<<endl;
                    break;
                case 2:
                    cout<<"Msg>ENTER U WANT VIEW WORD"<<endl;
                    cout<<"Input>"; cin>>word;
                    search(node , word); break;
                case 3:
                    cout<<"Input>"; cin>>word;
                    cout<<"Process>";
                    input(node,word); cout<<endl; break;
                case 4:
                    cout<<"Msg>ENTER U WANT DEL WORD"<<endl;
                    cout<<"Input>"; cin>>word;
                    delnum(node , word, key); break;
                default:
                    cout<<"ERROR>Invalid Select"<<endl;
                    break;
            }
        }
        cout<<endl;
    }
    delete[] node; node=NULL;
    cout<<"byebye"<<endl;
    return 0;
}