Thread: recursive string operation..

Originally Posted by transgalactic2

i didnt check for ascending order i need this part to work so i will start working on the
ascending order part

gotcha!

i cant use my own external functions either

i check index<255
if its larger then its not going further.

define your terminal condition when you reach the end of the string to prevent stack overflow.

Originally Posted by itCbitC

define your terminal condition when you reach the end of the string to prevent stack overflow.

i did define a terminal condition

its

Code:

if ((((str1[index1]>= 65) &&(str1[index1]<= 90))||((str1[index1]>= 97) &&(str1[index1]<= 122)))&&(index==254))
     {

         return 1;
     }

and

Code:

if(index1<255)

Originally Posted by transgalactic2

i check index<255
if its larger then its not going further.

redo the code with proper indentation; index is a local variable and everytime merge_strings() is invoked index is reset to zero due to this int res,index=0; in merge_strings().

Originally Posted by matsp

I'm not talking about EXTERNAL functions - or do you mean to say that the assignment clearly says that this has to be done in ONE FUNCTION? If so, I'd say it's worse than learning to tie your shoe-laces with one hand - you are now having to do it with one hand and your thumb and forefinger tied together with a sticking plaster. That is, it is utter lunacy to do this in ONE FUNCTION.

--
Mats

I completely agree with you

I could write external function
and later merge it with this one.

but the point is the recursion
i cant see where i going wrong.

Originally Posted by itCbitC

redo the code with proper indentation; index is a local variable and everytime merge_strings() is invoked index is reset to zero due to this int res,index=0; in merge_strings().

i changed the index=0 to index
now its giving me the exe error again

Code:

#include <stdio.h>
int merge_strings(char str1[], int index1,char str2[],int index2, char result[], int index3);
int main() {
    char input[255];
    char input2[255];
    char result[510];
    int index,flag,ch;
    printf("enter the first string \n");
 for (index = 0; index < 254 && (ch = getchar()) != '\n' && ch >=0; ++index)
    {
        input[index] = ch;
    }

    input[index] = '\0';

    printf("enter the second string \n");
 for (index = 0; index < 254 && (ch = getchar()) != '\n' && ch >=0; ++index)
    {
        input2[index] = ch;
    }

    input2[index] = '\0';
    flag=merge_strings(input, 0,input2,0, result, 0);

    if (flag)
    {
        printf("%s is valid.\n", result);
    }
    else
    {
        printf("input is invalid.\n");
    }

return 0;
}


int merge_strings(char str1[], int index1,char str2[],int index2, char result[], int index3)
 {
      int res,index;
      int res2;
      //start checking apha chars for string 1
     if ((((str1[index1]>= 65) &&(str1[index1]<= 90))||((str1[index1]>= 97) &&(str1[index1]<= 122)))&&(index==254))
     {

         return 1;
     }
     if (((str1[index1]>= 65) &&(str1[index1]<= 90))||((str1[index1]>= 97) &&(str1[index1]<= 122)))
     {

         res=merge_strings(str1, index++,str2,index2, result, index3);
     }
     else
     {
       return 0;
     }
     //end checking apha chars for string 1

      //start checking apha chars for string 2
    if ((((str1[index1]>= 65) &&(str1[index1]<= 90))||((str1[index1]>= 97) &&(str1[index1]<= 122)))&&(index==254))
       {

         return 1;
     }
     if (((str1[index1]>= 65) &&(str1[index1]<= 90))||((str1[index1]>= 97) &&(str1[index1]<= 122)))
     {

         res2=merge_strings(str1, index,str2,index2++, result, index3);
     }
     else
     {
       return 0;
     }
     //end checking apha chars for string 2

     if ((res==1)&&(res2==1))
     {
         result[index3]=str1[index];
         if(index1<255)
         {
             res=merge_strings(str1, index++,str2,index2, result, index3++);
         }

         result[index3]=str2[index2];
         if(index2<255)
         {
             res=merge_strings(str1, index,str2,index2++, result, index3++);
         }

     }
     return 1;
}