HCL interview question(Written)::Noida

Two programming questions asked by the HCL interviewing team.
Question 1::
Write a program in C/C++ which takes input as string "12345" and output will be:: 1+2+3+4+5=15.

I have written it in C. Below is the code.

Answer::

/* Input(as string)::"12345" and
output should be:: 1+2+3+4+5=15 */

#include<stdio.h>
#include<conio.h>
void main()
{
    char str1[]="12345";
    int i,sum=0;
    for(i=0;i<sizeof(str1)-1;i++)
    {
        printf("%d",(int)str1[i]-48);
        sum = sum + (int)str1[i]-48;
        if(i!=sizeof(str1)-2)
            printf("+");
    }
    printf(" = %d",sum);
}

Question 2:

Create two threads.

One thread prints only odd numbers 1 3 5 7 ...

other thread prints only even numbers 2 4 6 8 ...

But the output should be mixed of both :; 1 2 3 4 5 6 7 8 ...  upto n.

I had not worked in threads, so I have implemented the program in two function.

 If any one having idea of threads then please give the program, thanks in advance.

My program was as below::

#include<iostream>

using namespace std;

static int a,b;

void t_odd()

{

    a+=2;

    cout<<" "<<a;

}

void t_even()

{

    b+=2;

    cout<<" "<<b;

}

int main()

{

    a = -1; b = 0;

    int i,n;

     cout<<"enter the value n::";

    cin>>n;

    for(i=1;i<=n/2;i++)

    {

        t_odd();

        t_even();

    }

    if((n%2)!=0)

        t_odd();

    return 0;

}