//Merge Sort

#include <iostream.h>
#include <conio.h>
#define MAX 10

static int merge_arr[MAX+MAX],sort_arr[MAX+MAX];

class mergesort{
	int arr1[MAX],arr2[MAX],n1,n2,n3;
	public:
	void getdata();
	void showdata(int);
	void mergeLogic();
	void sortLogic();
};

void mergesort :: getdata(){
	int i;
	cout<<"\n--Data Must be Entered in Sorted Order for each Array--\n\n";
	cout<<"How many elements you require 1st -> Array: ";
	cin>>n1;
	for(i=0;i<n1;i++)
		cin>>arr1[i];
	cout<<"How many elements you require 2nd -> Array: ";
	cin>>n2;
	for(i=0;i<n2;i++)
		cin>>arr2[i];
	n3=n1+n2;
}

void mergesort :: showdata(int select){
	int i;
	if(select==1){
		cout<<"\n\n--Array 1--\n";
		for(i=0;i<n1;i++)
			cout<<arr1[i]<<"   ";
	}
	else if(select==2){
		cout<<"\n\n--Array 2--\n";
		for(i=0;i<n2;i++)
			cout<<arr2[i]<<"   ";
	}
	else if(select==3){
		cout<<"\n\n--Sorted Array--\n";
		for(i=0;i<n3;i++)
			cout<<sort_arr[i]<<"   ";
	}
}



void mergesort :: mergeLogic(){
	int i,j,c;
	for(i=0;i<n1;i++)
		merge_arr[i] = arr1[i];
	for(j=i,c=0;j<n3;j++,c++)
		merge_arr[j] = arr2[c];
}


void mergesort :: sortLogic(){
	//before sort call mergeLogic
	mergeLogic();

	int i,j,first=0,second=n1,third=n3;
	i=first;
	j=second;
	static int c=0;

	while(i<second && j<third){
		if(merge_arr[i] < merge_arr[j]){
			sort_arr[c]=merge_arr[i];
			i++;
		}
		else{
			sort_arr[c]=merge_arr[j];
			j++;
		}
		c++;
	}

	if(i<second){
		while(i<second){
			sort_arr[c]=merge_arr[i];
			i++;
			c++;
		}
	}

	if(j<third){
		while(j<third){
			sort_arr[c]=merge_arr[j];
			j++;
			c++;
		}
	}
}
/*

void mergesort :: sortLogic(){
	static int i,j,c=0;

	while(i<n1 && j<n2){
		if(arr1[i] < arr2[j]){
			sort_arr[c]=arr1[i];
			i++;
		}
		else{
			sort_arr[c]=arr2[j];
			j++;
		}
		c++;
	}

	if(i<n1){
		while(i<n1){
			sort_arr[c]=arr1[i];
			i++;
			c++;
		}
	}

	if(j<n2){
		while(j<n2){
			sort_arr[c]=arr2[j];
			j++;
			c++;
		}
	}

}
  */

void main(){
	clrscr();
	cout<<"\n*****Merge Sort*****\n";
	mergesort obj;
	obj.getdata();
	obj.sortLogic();
	obj.showdata(1);
	obj.showdata(2);
	obj.showdata(3);
	getch();
}