#include<stdio.h>
#include<stdlib.h>
int main()
{
	//to count number of times a button is pressed
	int index=0;
	//to store the input sequence
	char  input[50];
	//iterator through input
	int iterator = 0;

	printf("\n>Hello :) Welcome to the virtual mobile keypad\n");
	//read the code
	printf("\n>Enter code to decode : ");
	gets(input);
	printf("\n>You entered : ");
	//iterate through all the input characters
	while(input[iterator]!='\0')
	{
		//if consecutive characters(numbers) are same, then increment the index
		for(;input[iterator+1]!='\0';iterator++)
		{
			if(input[iterator]==input[iterator+1])
			index++;
			else
				break;
		}
		//if index is greater than number of characters a number can represent(i.e. digit 2 represent 3 characters a,b,c),
		//take the modulus to have circular pattern i.e a,b,c,a,b,c... )
		if(input[iterator]=='9' || input[iterator]=='7')
		{
			if(index>=4)
				index%=4;
		}
		else
		{
			index%=3;
		}
		switch(input[iterator])
		{
		case '2':	printf("%c",'a'+index);//if index = 0, print 'a'  //if index = 1, print b
					break;
		case '3':	printf("%c",'d'+index);
					break;
		case '4':	printf("%c",'g'+index);
					break;
		case '5':	printf("%c",'j'+index);
					break;
		case '6':	printf("%c",'m'+index);
					break;
		case '7':	printf("%c",'p'+index);
					break;
		case '8':	printf("%c",'t'+index);
					break;
		case '9':	printf("%c",'w'+index);
					break;

		case ' ':	break;					//' ' indicates a pause in input

		case '0':	printf(" ");			//'0' indicates a space
					break;
		default:	printf("\n\nError : Enter only numbers and space\n\n");
					//if other than 0-9 and ' ' is entered
					exit(0);
		}
		index=0;
		iterator++;
	}
	printf("\n\n");
	return 0;
}