Number Factorization

This

Code:

---

#include <stdio.h>
int main (void){
int i,value,factor1,factor2,remainder;

    printf("Please enter the inter you want to factor.\n");
    scanf("%d",&value);

for (i=1; i<=value; i++)
{
   
    remainder = value % i;
    if (remainder == 0)
      {
        factor1 = i;
        factor2 = value / i;
        printf("FACTOR 1 = %d\n", factor1);
        printf("FACTOR 2 = %d\n", factor2);   
        if (factor1>factor2)
        }
}
system("pause");

return 0;

}

---

In that case you want to use the break keyword to break out of the loop.

However, I note that just checking if factor1 >= factor2 would still result in unnecessary computation if say, value is a prime number. Still, get a working program first, and then optimise.

Program now works but is not breaking at the condition specified

Code:

---

#include <stdio.h>
int main (void){
int i,value,factor1,factor2,remainder;

    printf("Please enter the inter you want to factor.\n");
    scanf("%d",&value);

for (i=1; i<=value; i++)
{
   
    remainder = value % i;
    if (remainder == 0)
      {
        factor1 = i;
        factor2 = value / i;
        printf("FACTOR 1 = %d\n", factor1);
        printf("FACTOR 2 = %d\n", factor2);   
        if (factor1>factor2)
        break;
        }
       

}

system("pause");

return 0;

}

---

Quote:

---

Program now works but is not breaking at the condition specified

---

It is. The problem is that you print before checking the condition, so it appears as if the break is not working.

I put it before the print statements and it prints nothing

Can anyone tell me how to stop the loop so it doesnt repeat values

Please tell me what is the use of factor2 in your code. I just removed it.


Here's my code:

Code:

---

#include <stdio.h>
#include<stdlib.h>
int main (void){
int i,value,factor1,remainder;

    printf("Please enter the integer you want to factor.\n");
    scanf("&#37;d",&value);

for (i=1; i<=value; i++)
{
   
    remainder = value % i;
    if (remainder == 0)
      {
        factor1 = i;
        /*factor2 = value / i;*/
        printf("FACTOR = %d\n",factor1);
        /*printf("FACTOR 2 = %d\n", factor2);   
        if (factor1>factor2)
        break;*/
        }
       

}

system("pause");

return 0;

}

---

you should work on your indentation

Quote:

---

Please tell me what is the use of factor2

---

if 2 is factor of 10 then you know that 10/2 == 5 is also factor of 10
so you can get all factors of 10 just checking numbers 1,2,3 instead of 1,2,3,4,5,6,7,8,9,10
little ;) optimization - isn't it?

Quote:

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Originally Posted by vart

if 2 is factor of 10 then you know that 10/2 == 5 is also factor of 10
so you can get all factors of 10 just checking numbers 1,2,3 instead of 1,2,3,4,5,6,7,8,9,10
little ;) optimization - isn't it?

---

right.

But then the for statement should be

Code:

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for (i=1; i<=value/2; i++)

---

otherwise it will print the same factor twice and neither will the program be optimized coz its going through the same number of loops anyway.

or

Code:

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for (i=1; i*i<=value; i++)

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to print the sum of the factors do I use a loop?

Quote:

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Originally Posted by abk

right.

But then the for statement should be

Code:

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for (i=1; i<=value/2; i++)

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otherwise it will print the same factor twice and neither will the program be optimized coz its going through the same number of loops anyway.

---

No, that is incorrect. The limit is the square root, not half. For example, 12 = 3 *4 = 4 * 3. If we use half as the limit, we will still end up printing the (3, 4) pair and the (4, 3) pair since both 3 and 4 are less than 12/2=6.

Quote:

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to print the sum of the factors do I use a loop?

---

I do not recall you talking about calculating the sum of the factors, but it can be done as part of the loop that finds the factors.

to print the sum of the factors do I use a loop?

Quote:

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Originally Posted by clipsit

to print the sum of the factors do I use a loop?

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You already have a loop - that finds factors, same loop can calculate the sum

Quote:

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Originally Posted by tabstop

you can't declare new variables inside the parentheses of a for() statement

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Ahem, you are incorrect-ish sir.

Code:

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for(DWORD x = 0;x<Y;x++){
    }

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is perfectly valid C++ code, althoug since this is the C forum, it is technically incorrect, wlthough I doubt it woudl produce an error under most compilers.