https://www.spoj.com/problems/JULKA/

JULKA.cpp

////https://www.spoj.com/problems/JULKA/


/*
	*
	* 1. strings ko endpoint ni mil rha tha
	*	explicitly add '\0' at end of each char array like 112 => 112\0 
	* 2. index out of bound possible 
	*	garbage return hora tha
	*
	*
*/
#include <iostream>
#include <cstring>
#define debug(p) cout<<#p<<' '<<p<<'\n';
#define fr(v,s,n) for(int v=s;((s<n)?v<n:v>n);((s<n)?v++:v--))
#define cstop cin>>stop;
using namespace std;
char stop;
int main()
{

    int t=10;
    int size = 105;
    while (t--)
    {
        char app_together[size], app_more[size], app_together_untouched[size];
        cin>>app_together;
        cin>>app_more;
        for(int i=0; i<size; i++)
        {
            app_together_untouched[i] = app_together[i];
        }
        
        int len_app_together = strlen(app_together);
        int len_app_more = strlen(app_more);
        
        char ans[size];
        ans[len_app_together] = '\0';  // IMPORTANT : 1
        int flag = 1;
        for (int i=len_app_together-1; i>=0; i--)
        {
            if (flag)
            {
                for (int j=len_app_more-1; j>=0; j--)
                {
                    char a = app_together[i];
                    char b = app_more[j];
                    if(a >= b) { ans[i] = 48 + a - b; }
                    if(a < b)
                    {
                        ans[i] = 48 + (10 + a - b);
						app_together[i-1] -= 1;
					}
                    i--;
                }
            }
            flag = 0;
            /* CAUTION: index can get out of bound here when i = -1 */
            if (i > -1 && (int)app_together[i] + 1 == 48)  // IMPORTANT : 2
            {
                ans[i] = app_together[i] + 10;
                app_together[i-1] -= 1;
            }
            if (i > -1 && (int)app_together[i] >= 48) // IMPORTANT : 2
            {
            	ans[i] = app_together[i];
            }
        }
        int len_ans = strlen(ans);

        char final_ans[size];
        final_ans[len_ans] = '\0'; // IMPORTANT : 1
        int next_step_add = 0;
        for (int i=0 ; i < len_ans; i++)
        {
            int x = ans[i];
            x = x-48+next_step_add;
            if(x>=2)
            {
                if (x%2 == 0)
                {
                    final_ans[i] = x/2 + 48;
                    next_step_add = 0;
                }
                else
                {
                    final_ans[i] = x/2 + 48;
                    next_step_add=10;
                    continue;
                }
            }
            else
            {
                final_ans[i] = x/2 + 48;
                if (x%2 == 0)
                {
                    next_step_add = 0;
                }
                else
                {
                    next_step_add = 10;
                }
            }
        }
        int len_final_ans = strlen(final_ans);
        char final_ans_mod[size];
        int flag_for_zeros_before_num = 1;
        int counter =0;
        for(int i=0; i<=len_final_ans; i++)
        {
            if (final_ans[i] == '0' && flag_for_zeros_before_num)
            {
                counter++;
                continue;
            }
            else
            {
                final_ans_mod[i-counter] = final_ans[i];
                flag_for_zeros_before_num = 0;
            }
        }
	
        cout<<final_ans_mod<<"\n";
        char final_ans_klaudia[size];
        
        int len_final_ans_mod = strlen(final_ans_mod);
        int len_app_together_untouched = strlen(app_together_untouched);
        final_ans_klaudia[len_app_together_untouched] = '\0'; // IMPORTANT : 1
        flag = 1;
        for (int i=len_app_together_untouched-1; i>=0; i--)
        {
            if (flag)
            {
                for (int j=len_final_ans_mod-1; j>=0; j--)
                {
                    char a = app_together_untouched[i];
                    char b = final_ans_mod[j];
                    if(a >= b)
                    {
                        final_ans_klaudia[i] = 48 + a - b;
                    }
                    if(a < b)
                    {
                        final_ans_klaudia[i] = 48 + (10 + a - b);
                        app_together_untouched[i-1] -= 1;
                    }
                    i--;
                }
            }
            flag = 0;
            if (i > -1 && (int)app_together_untouched[i] + 1 == 48) // IMPORTANT : 1
            {
                final_ans_klaudia[i] = app_together[i] + 10;
                app_together_untouched[i-1] -= 1;
            }
            if (i > -1 && (int)app_together_untouched[i] >= 48) // IMPORTANT : 1
            {
                final_ans_klaudia[i] = app_together_untouched[i];
            }
        }

        int len_final_ans_klaudia = strlen(final_ans_klaudia);
        flag_for_zeros_before_num = 1;
        for(int i=0; i<len_final_ans_klaudia; i++)
        {
            if (final_ans_klaudia[i] == '0' && flag_for_zeros_before_num)
            {
                continue;
            }
            else
            {
                flag_for_zeros_before_num = 0;
                cout<<final_ans_klaudia[i];
            }
        }
        cout<<"\n";

    }
    return 0;
}

Cool! @garganshul108
I actually thought that the problem may be related to the null character.
And thanks for pointing out the case where the index went out of bounds.
I totally missed that.
Finally solved.
Thanks for debugging. :) 💯

Even this has a minor mistake.
Try running this with input
100
2 .
I've corrected that in the final submission.
Here -> (https://gist.github.com/AnirudhDagar/6aac9a15e6072aa9eac5f8be57caf352)

Even this has a minor mistake.
Try running this with input
100
2 .
I've corrected that in the final submission.
Here -> (https://gist.github.com/AnirudhDagar/6aac9a15e6072aa9eac5f8be57caf352)

UNPOSSIBLE XD