Question

Trace the following program, showing the values of the variables and the output generated by the program. The input file to the program is:

1375 3

8472 2

(SHOW YOUR WORK)

#include <stdio.h>

#define BASE 10

int find( int, int);

int extract( int, int);

main()

{

int a, b; int c, d;

while( scanf("%d", &a) != EOF)

{ scanf("%d", &b);

c = find(a, b);

if(c >= 0)

d = extract(a, c);

else d = c;

printf("its %d \n", d);

}

}

int find(int a, int b)

{ int i = 0;

while( a % BASE != b)

{ a = a / BASE;

if(a == 0) return -1;

i = i + 1;

}

return i;

}

int extract(int a, int b)

{

while(b)

{

a = a / BASE;

b = b - 1;

}

return a % BASE;

}

Answer 1

/* Output of above program with sample input give as above is as follows */

/* Program tracing to find values of variables */

/*Changes done in above code to show above output are marked in bold in below code */

#include <stdio.h>

#define BASE 10

int find( int, int);

int extract( int, int);

int main()

{

  

int a, b; int c, d;

  

while( scanf("%d", &a) != EOF)

  

{ scanf("%d", &b);

  

c = find(a, b);

  

printf("\n");

printf("value of c is %d \n",c);

  

if(c >= 0){

  

d = extract(a, c);

printf("value of d if c is greater than zero is %d \n",d);

  

}

else d = c;

  

printf("its %d \n", d);

  

}

  

}

int find(int a, int b)

{ int i = 0;

  

while( a % BASE != b)

  

{ a = a / BASE;

  

if(a == 0) return -1;

  

i = i + 1;

  

}

  

return i;

  

}

int extract(int a, int b)

{

  

while(b)

  

{

  

a = a / BASE;

  

b = b - 1;

  

}

  

return a % BASE;

  

}