#include<iostream>				//pgm to implement string functions
#include<string>
using namespace std;
int main()
{
	string str1, str2, str3;
	char ch, s1[30],s2[30];
	int opt,pos,spos,num,found;
	cout<<"\nEnter the main string : \n";
	gets(s1);
	str1=s1;
	cout<<"\nEnter the second string : \n";
	gets(s2);
	str2=s2;
	do
	{
		cout<<"\nEnter option : \n1 - Compare String\n2 - Append String\n3 - Insert String\n4 - Find String\n";
		cout<<"5 - Erase String\n6 - Check if substring\n7 - Replace String\n8 - Assign String\n";
		cout<<"9 - + String\n10 - = String\n11 - == String\n12 - > String\n13 - < String\n\n";
		cin>>opt;
		switch(opt)
		{
			case 1:
				if (str1.compare(str2) != 0)
    					cout <<"\nThe strings are not the same";
				else
					cout <<"\nBoth the strings are same";
    				break;
    			case 2:
    				str1.append(str2);
    				cout<<str1;
    				break;
    			case 3:
    				cout<<"\Enter the position for inserting the string : ";
    				cin>>pos;
    				str1.insert(pos,str2);
    				cout<<str1;
    				break;
    			case 4:
    				found=str1.find(str2);
 				if (found!=string::npos)
    					cout <<str2<<" found at: " <<int(found)<<endl;
    				else
    					cout<<"\nThe string is not found ! ";
       				break;
    			case 5:
    				cout<<"\nEnter the starting position to be erased : ";
    				cin>>spos;
    				cout<<"\nEnter the number of letters to be erased : ";
    				cin>>num;
    				str1.erase (spos,num);
  				cout<<"\n"<<str1<<endl;
  				break;
  			case 6:
  				cout<<"\nEnter the starting position of the required substring : ";
    				cin>>spos;
    				cout<<"\nEnter the number of letters needed : ";
    				cin>>num;
  				str2 = str1.substr (spos,num);
  				cout<<"\n"<<str2<<endl;
  				break;
  			case 7:
  				cout<<"\nEnter the starting position from which the string is to be replaced : ";
  				cin>>pos;
  				cout<<"\nEnter the number of spaces to be replaced : ";
  				cin>>spos;
  				str1.replace(pos,spos,str2);
  				cout<<"\n"<<str1;
  				break;
  			case 8:
  				cout<<"\nEnter the starting position from which the string is to be assigned : ";
  				cin>>pos;
  				cout<<"\nEnter the number of spaces to be assigned : ";
  				cin>>spos;
  				str2.assign(str1,pos,spos);
  				cout<<"\n"<<str1;
  				break;
  			case 9:
  				str3=str1+str2;
  				cout<<"\n"<<str3;
  				break;
    			case 10:
  				str1=str2;
  				cout<<"\n"<<str1<<endl;
  				break;
  			case 11:
  				if(str1==str2)
  					cout<<"\nBoth the strings are equal";
  				else
  					cout<<"\nBoth the strings are not equal";
  				break;
  			case 12:
  				if(str1>str2)
  				{
  					cout<<"\nThe first string is greater than the second!\n";
  					cout<<str1<<" is greater than "<<str2<<"\n";
  				}
  				else if(str2>str1)
  				{
  					cout<<"\nThe second string is greater than the first!\n";
  					cout<<str2<<" is greater than "<<str1<<"\n";
  				}
  				else
  					cout<<"\nEqual";
  				break;
  			case 13:
  				if(str1<str2)
  				{
  					cout<<"\nThe first string is smaller than the second!\n";
  					cout<<str1<<" is smaller than "<<str2<<"\n";
  				}
  				else if(str2<str1)
  				{
  					cout<<"\nThe second string is greater than the first!\n";
  					cout<<str2<<" is smaller than "<<str1<<"\n";
  				}
  				else
  					cout<<"\nEqual";
  				break;
  			default:
    				cout<<"\nInvalid option";
    		}
    		cout<<"\nDo you want to continue? [y/n] : ";
    		cin>>ch;
    	}while(ch=='y'||ch=='Y');
}