FuriousMathematician - 9 months ago 55

C Question

I've been asked to factorize a number and show it in a specific way .

e.g: 100 = 2^2*5^2

This is the C++ code I've used so far with no dice , unfortunately:

`#include <stdio.h>`

#include <math.h>

//IsPrime indicates whether a given number is or is not prime.

bool IsPrime(long long n)

{

int j = 3;

if (n == 2)

{

return true;

}

else if (n % 2 == 0)

{

return false;

}

else

{

for (j = 3; j <= sqrt(n); j += 2)

{

if (n%j == 0)

{

return false;

}

}

}

return true;

}

int main(void)

{

long long n_orig,n, i=3 , primecount=0;

scanf("%lld", &n_orig);

n = n_orig;

if (n == 1)

{

printf("1");

return 0;

}

if (IsPrime(n))

{

printf("%lld", n);

return 0;

}

if (n % 2 == 0)

{

while (n >= 2 && n % 2 == 0)

{

primecount++;

n = n / 2;

}

if (primecount == 1)

{

printf("2*");

}

else

{

printf("2^%lld*", primecount);

}

}

primecount = 0;

n = n_orig;

while (i <= n/2)

{

if (IsPrime(i))

{

while (n >= i && n % i == 0)

{

primecount++;

n = n / i;

}

}

n = n_orig;

if (primecount == 0)

{

i++;

continue;

}

if (primecount == 1)

{

printf("%lld*", i);

}

else

{

printf("%lld^%lld*", i, primecount);

}

primecount = 0;

i+=2;

}

printf("\b");

return 0;

}

Using this code I was able to generate a few test cases, though when I uploaded my answer to the website where the codes are presumably evaluated , out of 7 test cases (which I cannot know what they exactly are) ,

Also , I don't really wanna know if my answer could be improved in some way ,

P.S : Usage of

Thanks in advance.

Answer Source

Try this:

```
#include <stdio.h>
#include <math.h>
unsigned long long PrintMultiplicity(unsigned long long n,unsigned long long factor)
{
int count = 0;
while (n%factor == 0)
{
count++;
n /= factor;
}
if (count > 0)
{
printf("%llu^%d",factor,count);
if (n > 1)
printf("*");
}
return n;
}
void PrintFactorization(unsigned long long n)
{
unsigned long long factor;
int add;
printf("%llu = ",n);
n = PrintMultiplicity(n,2);
n = PrintMultiplicity(n,3);
for (factor = 5, add = 2; factor <= sqrt(n); factor += add, add = 4-add)
n = PrintMultiplicity(n,factor);
if (n > 1)
printf("%llu^1",n);
printf("\n");
}
int main()
{
unsigned long long n;
scanf("%llu",&n);
PrintFactorization(n);
return 0;
}
```