C++ programme for function that will scan a string for the occurrence of a given string for substring

#include<iostream.h>

#include<conio.h>

#include<stdio.h>

char *substr(char *string1,char *string2)

{

               char *cp;

               cp=NULL;

               int n=0;

               while(*string1!='\0')

               {

                              if(*string1==*string2)

                              {

                                             n=1;

                                             cp=string1;

                                             while(*string2!='\0')

                                             {

                                                            if(*string1!=*string2)

                                                            {

                                                                           n=0;

                                                                           cp=NULL;

                                                                           break;

                                                            }

                                                            string1++;

                                                            string2++;

                                             }

                              }

                              string1++;

               }

               return cp;

}

void main()

{

               clrscr();

               char str[50],sub[50];

               char *pos;

               cout<<"\nEnter  a string \n";

               gets(str);

               cout<<"\nEnter a string to searched\n";

               gets(sub);

               pos=substr(str,sub);

               if(*pos)

               {

                              cout<<"\nString found\n";

               }

               else

               {

                              cout<<"\nString not found\n";

               }

               getch();

}

OUTPUT:

Enter  a string                                                                

KARTHIK RAO 88

                                                                               

Enter a string to searched                                                     

RAO                                                                             

                                                                               

String found