Thread: string question

im trying to add a number like 1234567891112131415 and 1234567891234567891234556. i stored them both as string1 and string2 but i cant figure out how to get the answer.i think i need to use strtol, but i cant figure out what am i doing wrong. any help?

Code:

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

int main() {
     // variables
     char string1[512];
     char string2[512];
    
     //opening
     printf("Enter a whole number:");
     scanf_s("%s", string1);
     printf("Enter another whole number:");
     scanf_s("%s", string2);
     //adding trying to use strtol function
     long strtol(char *string1, char** string2);

    

     //results
     printf("The sum is:%s",  );
    
     //exiting
     getchar();
     getchar();
     return 0;
}

giggle giggle, i guess you dont know the answer either.

by adding, but what im adding is too big for regular int, float, long long int, i need to add it as string but cant figure out how to.

Add just like you would do when you calculate manually.
Write down the steps when you add.
eg.

Code:

32324
   343

ok, i guess im not making myself clear.read the title befor you post a comment, it didnt say how do i add, im not new new to c programming, im just stuck on a problem and need help. i know how to add small numbers, i made myself clear with i need to add too large numbers ie.1234567890123456789 + 9999999999999999999999999999, and get an answer, but the answer is too big for int, long int, long long int, or float value. so i think i need to use strings? any guesses?

if you want to code how to calculate large numbers you will have to do one of two things:

1.) Invest some time looking for Binary-coded decimal (BCD) code in C, and how to use it.

2.) Create functions to calculate the numbers bit by bit.
For example, "134" + "396" would mean nothing because they are both in strings, so you'd have to make a function to add the strings. (I know its a small number, but this is just an example)

You'd start with "4" + "6". First you'd need to turn them into ints, calculate it (which would be 10), then turn it into a string which would equal "10". Then continuing with "30" + "90" + "10" which would equal "130". Then finishing it off by adding "100" with "300" and "130" which would equal "530".

Something like this would require you to know recursion (or if you want to just use loops, its possible) and a small knowledge of the standard library to turn the strings to ints, calculate them, and then back to strings.

so your saying rite a code that reads up and down rite to left?
i didnt think you could do that. how would that work. also if i rite a code to do that would i just store it as regualr int or still use string. im confused.

Originally Posted by rupert

so your saying rite a code that reads up and down rite to left?
i didnt think you could do that. how would that work. also if i rite a code to do that would i just store it as regualr int or still use string. im confused.

Of course you can do that... But I'm not going to hand you the answer (and neither should anyone else).

A sizeable chunk of a programmer's skill is the analytical skill to understand the nuts and bolts of a problem then applying logical thinking to work out a solution... Writing code is the second to last step in the process...

So break it down into the smallest steps... What has to happen first?

Originally Posted by claudiu

You need to learn how to read and write proper English before you can push yourself to learn how to add. If you want to be taken seriously, act like you take yourself seriously not like a bloody joker.

Assuming that English is his first language?