//OPERATIONS ON A STRING

#include<stdio.h>
#include<string.h>

void main()
{

char str1[20],str2[20];
int i,j,k,opt,flag=0,count=0;
clrscr();

printf("Enter the string\n");
gets(str1);

do
 {
 clrscr();
 puts(str1);
 printf("\n1.No of Occurances of a word\n2.Print Abbrevated form\n");
 printf("3.Extract a Substring\n4.Reverse a given string\n");
 printf("5.Delete all occurances of vowels\n6.Exit\n");


 printf("Enter the option\n");
 scanf("%d",&opt);
 flushall();
  switch(opt)
	 {
	 case 1:
		{
		count=0;
		printf("Enter the search string\n");
		gets(str2);

		for(i=0;i<strlen(str1);i++)
			{
			if(str2[0]==str1[i])
			  {
			  for(j=0,k=i;str1[k]!='\0'&&str2[j]!='\0';j++,k++)
				  {
				  if(str2[j]!=str1[k])
					 {
					 flag=0;
					 break;
					 }
					 else
					 flag=1;
					}
			  if(flag==1)
				 count++;
			  }
			}

		printf("Occurances:%d",count);
		getch();
		clrscr();
		break;
		}


	 case 2:
		{
					//ABBREVATION
		count=1;
		str2[0]=toupper(str1[0]);

		for(i=0;str1[i]!='\0';i++)
			{
			if(str1[i]==' ')
			  {
			  str2[count]=toupper(str1[i+1]);
			  count++;
			  }
			}
			str2[count]='\0';
			printf("Abbrevated form is\n");
			puts(str2);
		getch();
		//clrscr();
		break;
		}

	 case 3:
		{
				  //EXTRACT SUBSTRING
		int pos1,pos2;

		printf("Enter the initial position\n");
		scanf("%d",&pos1);
		printf("Enter the final position\n");
		scanf("%d",&pos2);

		if((pos1<=0)||(pos1>strlen(str1))||(pos2<pos1))
		  printf("Please check given positions are correct\n");

		  else
		  for(i=0;i<=strlen(str1);i++)
			  {
			  if((i+1)==pos1)
				 {
				 for(j=0;j<=(pos2-pos1);j++,i++)
					 {
					 str2[j]=str1[i];
					 }

				 str2[j]='\0';
				 printf("Extracted string\n");
				 puts(str2);
				 break;
				 }
			  }

		getch();
		flushall();
		clrscr();
		break;
		}

	 case 4:
		{
					//REVERSE

		for(i=0;i<strlen(str1);i++)
			{
			str2[i]=str1[strlen(str1)-i-1];
			}
		str2[i]='\0';

		puts(str2);

		getch();
		clrscr();
		break;
		}

	 case 5:
		{
					//DELETE VOWELS

		for(i=0,j=0;i<=strlen(str1);i++,j++)
			{
			switch(toupper(str1[i]))
					{
					case 'A':
								{
								j--;
								break;
								}
					case 'E':
								{
								j--;
								break;
								}
					case 'I':
								{
								j--;
								break;
								}
					case 'O':
								{
								j--;
								break;
								}
					case 'U':
								{
								j--;
								break;
								}
					default:
								{
								str2[j]=str1[i];
								}

					}
			}

		printf("String without vowels\n");
		puts(str2);
		getch();
		clrscr();
		break;
		}
	 case 6:
		exit();

	 default:
		printf("Invalid Entry!\n");
		getch();
		clrscr();

	 }

 }while(opt!=6);
}
/*
SAMPLE OUTPUT

hello how are you

1.No of Occurances of a word
2.Print Abbrevated form
3.Extract a Substring
4.Reverse a given string
5.Delete all occurances of vowels
6.Exit
Enter the option
1
Enter the search string
how
Occurances:1
_______________________________________
hello how are you

1.No of Occurances of a word
2.Print Abbrevated form
3.Extract a Substring
4.Reverse a given string
5.Delete all occurances of vowels
6.Exit
Enter the option
2
Abbrevated form is
HHAY
_______________________________________
*/