Translating alphabetic number in C

crystal2005

Hi guys,

Just like the title, i'm looking for the example of C program that translates an alphabetic phone number into numeric. The idea as the following output

Enter phone number: 1800-TEST-100

result: 1800-8378-100

so basically 2=ABC, 3=DEF, 4=GHI, . . . , 9 = WXYZ

So, all the non-alphabetic (E.g. dash, punctuations) will leave unchanged.

Can anyone give the pseudo code of how to handle the string input of the above idea??

Thank you.

ricardopf

Actually, it seems to be an "light problem"...
All you need to do is write an "while" or a "for" loop.
The loop should go from 0 (zero) to the ALPH_PHONE_SIZE-1.
Probably you will read the phone from the user and store the information in a array char (or string).
Then, inside the loop you should access each position of this array/string and compute the information.
If you use a "while" loop you must keep a counter manually in order to access the array/string positions gradually. Otherwise, using a "for" loop you access the position with the loop control variable.
To know what character is the contend of a specific array/string position, you can implement a "switch:case" structure.
For example:

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...

// inside the loop

switch (phone_array[POS]):

   case 'a':

   case 'b':

   case 'c':

      value = 2;

      break;

   case 'd':

   case 'e:

   case 'f':

      value = 3;

      break;

...

   default:

      break;

...

newb16

If maintainability is not an issue, I'd rather use lookup array and index it by input letter ( converted to upper case beforehand):
res = lookup[letter-'A'];
where array is like
int lookup[] = {2,2,2,3,3, ... };

whodgson

The following comments explain the code amplified algorithm. The convert() function is certainly a bit clunky and could do with an oil change.

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 {char a[25]={0};                            

char c=0;

while(cin.get(c) )                        //get the alpha-numeric string

{ for(int i=0;i<25;i++)

 a[i]=c;                                      //place each in array

 if(c>=0 && c<=9)cout.put(c);       //traverse array and print integers

 else if(c>='A' && c<='Z')convert(c);  //call func to convert text

 else cout.put(c);}                        //print any integers which follow

}

End input with Ctrl+Z.

Expand|Select|Wrap|Line Numbers

 char convert (char c)         //convert function - text to ints

{

switch (c)

{case 65:cout<<"2";break; //A

 case 66: cout<<"2";break; //B

 case 67: cout<<"2";break; //C    

 case 68: cout<<"3";break; //D

 case 69: cout<<"3";break; //E       

 case 70: cout<<"3";break; //F

............etc.......................... 

case 87: cout<<"9";break; //W

 case 88: cout<<"9";break; //X    

 case 89: cout<<"9";break; //Y

 case 90: cout<<"9";break; //Z       

 default:cout<<" ";break; }                     

}

/*
This is typical output.
1300-WIDER-32541-100^Z
1300-94337-32541-100

1800-THINNER-25416-100^Z
1800-8446637-25416-100^Z
Press any key to continue . .
*/
End program with another Ctrl+Z
Hope this helps.

JosAH

Quote:

Originally Posted by whodgson

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 char convert (char c)         //convert function - text to ints

{

switch (c)

{case 65:cout<<"2";break; //A

 case 66: cout<<"2";break; //B

 case 67: cout<<"2";break; //C    

 case 68: cout<<"3";break; //D

 case 69: cout<<"3";break; //E       

 case 70: cout<<"3";break; //F

............etc.......................... 

case 87: cout<<"9";break; //W

 case 88: cout<<"9";break; //X    

 case 89: cout<<"9";break; //Y

 case 90: cout<<"9";break; //Z       

 default:cout<<" ";break; }                     

}

Please don't try to outsmart anything and don't use those absolute values; your code fails horribly on non-ASCII encoding machines (EBCDIC is still around and alive and kicking). Use symbolic constants instead: 'A', 'B', 'C' etc. Your compiler knows what to do with them.

kind regards,

Jos

whodgson

The convert() function in thread #4 was badly written and wrong.
It should have been expressed as follows:
char convert (char c)
{
switch (c)
{case 'A':cout<<"2";break;
case 'B': cout<<"2";break;
case 'C': cout<<"2";break;
case 'D': cout<<"3";break;
case 'E': cout<<"3";break;
case 'F': cout<<"3";break;
--------------etc-------------------
case 'S': cout<<"7";break;
case 'T': cout<<"8";break;
case 'U': cout<<"8";break;
case 'V': cout<<"8";break;
case 'W': cout<<"9";break;
case 'X': cout<<"9";break;
case 'Y': cout<<"9";break;
case 'Z': cout<<"9";break;
default:cout<<" ";break; }
}
Thanks JosAH.....afraid am a VSL

JosAH

Why not use the short solution given in reply #3? Something like this:

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char* d= "222333444 ... 77778889999";

if (c >= 'A' && c <= 'Z') cout << d[c-'A'];

kind regards,

Jos

crystal2005

Quote:

Originally Posted by whodgson

The convert() function in thread #4 was badly written and wrong.
It should have been expressed as follows:
char convert (char c)
{
switch (c)
{case 'A':cout<<"2";break;
case 'B': cout<<"2";break;
case 'C': cout<<"2";break;
case 'D': cout<<"3";break;
case 'E': cout<<"3";break;
case 'F': cout<<"3";break;
--------------etc-------------------
case 'S': cout<<"7";break;
case 'T': cout<<"8";break;
case 'U': cout<<"8";break;
case 'V': cout<<"8";break;
case 'W': cout<<"9";break;
case 'X': cout<<"9";break;
case 'Y': cout<<"9";break;
case 'Z': cout<<"9";break;
default:cout<<" ";break; }
}
Thanks JosAH.....afraid am a VSL

Ahh... this works fine. Thanks a lot guys :)

But my program has different implementation. I used for loop to traverse all the character inside the char array and put the array into the switch case.

whodgson

I couldn`t see how Newb16`s lookup worked and thought that it was a germ of an idea that had to be developed. Now that you`ve repeated it, think I can see
(vaguely) its meaning....... so will have a play with it. Thanks to you both.

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