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strider496 · Mar 23rd, 2005, 11:25 AM

The greatest common divisor of integers x and y is the largest integer that evenly divides both x and y. Write a recursive function gcd taht returns the greatest common divisor of x and y. The gcd of x and y is defined recursively as follows: If y is equal to 0, then gcd(x,y) is x; otherwise gcd(x,y) is gcd(y,x%y) where % is remainder operator.

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#include <stdio.h>

long gcd (int,int);

int main()
{
	int x,y,i;

	for (i=0; i<=100; i++)
	{
		printf("Enter 1st integer\n");
		scanf("%d",&x);

		printf("Enter 2nd integer\n");
		scanf("%d",&y);
	}

	return 0;
}

long gcd (int x,int y)
{
	if (y)
	{
		return gcd(y, x%y);
	}

    else
    {
	   return x;
    }

 return 0;
}

prblem im having is that it keeps on asking me to enter 1st integer and 2nd integers

peace_of_mind · Mar 23rd, 2005, 12:22 PM

*EDIT* It's a function you're writing. I promise to read it completely from now on :o */EDIT*

The loop will continue to run as long as the conditions are being met. To test it, add a printf to see if the results are correct.

strider496 · Mar 23rd, 2005, 2:59 PM

(Toggle Plain Text)

#include <stdio.h>

int gcd(int a, int b);

int main()
{
  int x, y, z;
  int gcd(int, int);
  
  printf("Enter 1st integer\n");
  scanf("%d",&x);

  printf("Enter 2nd integer\n");
  scanf("%d",&y);

  if(y==0)
  {
    z = gcd(x, y);
    printf("gcd(%d,%d) is %d\n" x,y,z ;}
  else
    printf("gcd(%d,%d is gcd(%d, %d %% %d)\n",x,y,x,x%y);
}

int gcd(int a, int b)
{
  while (a != b){
    if (a > b)
      a -= b;
    else
      b -= a;
  }
  return a;
}

spydoor · Mar 23rd, 2005, 3:19 PM

Your first post was correct you just never called the function.

You new gcd function is not recursive. A recursive function is a function that calls itself.

(Toggle Plain Text)

#include <stdio.h>

long gcd (int,int);

int main()
{
    int x,y,i,z;

    printf("Enter 1st integer\n");
    scanf("%d",&x);

    printf("Enter 2nd integer\n");
    scanf("%d",&y);

    z = gcd(x,y);

    printf("gcd is %d\n", z);

    return 0;
}

long gcd (int x,int y)
{
    if (y) {
        return gcd(y, x%y);
    }else {
       return x;
    }
}

strider496 · Mar 24th, 2005, 11:31 AM

thx guys got my programs to run

Mar 23rd, 2005, 11:25 AM	#1
strider496 Newbie Join Date: Mar 2005 Posts: 10 Rep Power: 0	Greatest common divisor program The greatest common divisor of integers x and y is the largest integer that evenly divides both x and y. Write a recursive function gcd taht returns the greatest common divisor of x and y. The gcd of x and y is defined recursively as follows: If y is equal to 0, then gcd(x,y) is x; otherwise gcd(x,y) is gcd(y,x%y) where % is remainder operator. (Toggle Plain Text) #include <stdio.h> long gcd (int,int); int main() { int x,y,i; for (i=0; i<=100; i++) { printf("Enter 1st integer\n"); scanf("%d",&x); printf("Enter 2nd integer\n"); scanf("%d",&y); } return 0; } long gcd (int x,int y) { if (y) { return gcd(y, x%y); } else { return x; } return 0; } #include <stdio.h> long gcd (int,int); int main() { int x,y,i; for (i=0; i<=100; i++) { printf("Enter 1st integer\n"); scanf("%d",&x); printf("Enter 2nd integer\n"); scanf("%d",&y); } return 0; } long gcd (int x,int y) { if (y) { return gcd(y, x%y); } else { return x; } return 0; } prblem im having is that it keeps on asking me to enter 1st integer and 2nd integers Last edited by strider496; Mar 23rd, 2005 at 3:07 PM.

Mar 23rd, 2005, 12:22 PM	#2
peace_of_mind Professional Programmer Join Date: Sep 2004 Location: Hell if I know most of the time Posts: 439 Rep Power: 4	EDIT It's a function you're writing. I promise to read it completely from now on :o /EDIT The loop will continue to run as long as the conditions are being met. To test it, add a printf to see if the results are correct. __________________ Amateurs built the ark Professionals built the Titanic Last edited by peace_of_mind; Mar 23rd, 2005 at 12:28 PM.

Mar 23rd, 2005, 2:59 PM	#3
strider496 Newbie Join Date: Mar 2005 Posts: 10 Rep Power: 0	revise prog (Toggle Plain Text) #include <stdio.h> int gcd(int a, int b); int main() { int x, y, z; int gcd(int, int); printf("Enter 1st integer\n"); scanf("%d",&x); printf("Enter 2nd integer\n"); scanf("%d",&y); if(y==0) { z = gcd(x, y); printf("gcd(%d,%d) is %d\n" x,y,z ;} else printf("gcd(%d,%d is gcd(%d, %d %% %d)\n",x,y,x,x%y); } int gcd(int a, int b) { while (a != b){ if (a > b) a -= b; else b -= a; } return a; } #include <stdio.h> int gcd(int a, int b); int main() { int x, y, z; int gcd(int, int); printf("Enter 1st integer\n"); scanf("%d",&x); printf("Enter 2nd integer\n"); scanf("%d",&y); if(y==0) { z = gcd(x, y); printf("gcd(%d,%d) is %d\n" x,y,z ;} else printf("gcd(%d,%d is gcd(%d, %d %% %d)\n",x,y,x,x%y); } int gcd(int a, int b) { while (a != b){ if (a > b) a -= b; else b -= a; } return a; }

Mar 23rd, 2005, 3:19 PM	#4
spydoor Programmer Join Date: Feb 2005 Posts: 64 Rep Power: 4	Your first post was correct you just never called the function. You new gcd function is not recursive. A recursive function is a function that calls itself. (Toggle Plain Text) #include <stdio.h> long gcd (int,int); int main() { int x,y,i,z; printf("Enter 1st integer\n"); scanf("%d",&x); printf("Enter 2nd integer\n"); scanf("%d",&y); z = gcd(x,y); printf("gcd is %d\n", z); return 0; } long gcd (int x,int y) { if (y) { return gcd(y, x%y); }else { return x; } } #include <stdio.h> long gcd (int,int); int main() { int x,y,i,z; printf("Enter 1st integer\n"); scanf("%d",&x); printf("Enter 2nd integer\n"); scanf("%d",&y); z = gcd(x,y); printf("gcd is %d\n", z); return 0; } long gcd (int x,int y) { if (y) { return gcd(y, x%y); }else { return x; } }

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Mar 24th, 2005, 11:31 AM	#5
strider496 Newbie Join Date: Mar 2005 Posts: 10 Rep Power: 0	thx guys got my programs to run

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Programming Forums > Application Development > C++

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